ncbi.com
Free website and domain report on ncbi.com
Last Updated: 13th January, 2023 Update Now
Overview
Snoop Summary for ncbi.com
This is a free and comprehensive report about ncbi.com. Ncbi.com is hosted in Napa, California in United States on a server with an IP address of 50.233.240.133, where USD is the local currency and the local language is English. Ncbi.com has the potential to be earning an estimated $1 USD per day from advertising revenue. If ncbi.com was to be sold it would possibly be worth $1,009 USD (based on the daily revenue potential of the website over a 24 month period). Ncbi.com receives an estimated 480 unique visitors every day - a decent amount of traffic! This report was last updated 13th January, 2023.
About ncbi.com
| Site Preview: |   |
| Title: | Home Page - NCB Management Services, Inc. |
| Description: | |
| Keywords and Tags: | business |
| Related Terms: | ncb |
| Fav Icon: | |
| Age: | Over 26 years old |
| Domain Created: | 21st April, 1998 |
| Domain Updated: | 12th June, 2022 |
| Domain Expires: | 20th April, 2026 |
Review
Snoop Score
1/5
Valuation
$1,009 USD
Note: All valuation figures are estimates.
Popularity
Low
Note: Popularity is estimated.
Rank, Reach and Authority
| Alexa Rank: | 1,438,981 |
| Alexa Reach: | |
| SEMrush Rank (US): | |
| SEMrush Authority Score: | |
| Moz Domain Authority: | 0 |
| Moz Page Authority: | 0 |
Organic vs Paid (Google Ads)
Traffic
Visitors
| Daily Visitors: | 480 |
| Monthly Visitors: | 14,608 |
| Yearly Visitors: | 175,185 |
Note: All visitors figures are estimates.
Visitors By Country
Revenue
Revenue
| Daily Revenue: | $1 USD |
| Monthly Revenue: | $42 USD |
| Yearly Revenue: | $499 USD |
Note: All revenue figures are estimates.
Revenue By Country
SEO
Backlinks Analysis (SEMrush)
Top New Follow Links
Top Ranking Keywords (US)
Domain Analysis
| Value | Length | |
|---|---|---|
| Domain: | ncbi.com | 8 |
| Domain Name: | ncbi | 4 |
| Extension (TLD): | com | 3 |
| Expiry Check: | |
Page Speed Analysis
| Average Load Time: | |
| Load Time Comparison: |
PageSpeed Insights
Avg. (All Categories)
Performance
Accessibility
Best Practices
SEO
PWA
0–49 (Fail) 50–89 (Average) 90–100 (Pass) 
URL: https://ncbi.com/
Updated: 13th January, 2023
Simulate loading on desktop
Performance
Indicates how well the page is performing and highlights opportunities where performance may be improved for ncbi.com. This includes details about optimizing page load times which can result in a better user experience.Metrics
Time to Interactive — 1.5 s The time taken for the page to become fully interactive.
Total Blocking Time — 10 ms The total blocking time is the sum of all time periods between First Contentful Paint and Time to Interactive (when task length exceeded 50ms).
Cumulative Layout Shift — 0 Cumulative Layout Shift is the measurement of visible elements collective movement within the viewport.
View Data
Audits
Max Potential First Input Delay — 80 ms Users could experience a delay when interacting with the page.
Network Requests Below is a list of network requests that were made during page load.
| URL | Protocol | Start Time (Ms) | End Time (Ms) | Transfer Size (Bytes) | Resource Size (Bytes) | Status Code | MIME Type | Resource Type |
|---|---|---|---|---|---|---|---|---|
| http://ncbi.com/ | http/1.1 | 0 | 69.249000021955 | 318 | 0 | 301 | text/html | |
| https://ncbi.com/ | h2 | 69.625000003725 | 237.96900000889 | 24697 | 24381 | 200 | text/html | Document |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | h2 | 246.03800001205 | 402.07599999849 | 11440 | 11095 | 200 | text/javascript | Script |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | h2 | 246.16900002002 | 345.01800002181 | 121144 | 120805 | 200 | text/css | Stylesheet |
| https://ncbi.com/Site.css | h2 | 246.31800001953 | 381.26100000227 | 17638 | 17348 | 200 | text/css | Stylesheet |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | h2 | 246.60600000061 | 456.06600001338 | 145788 | 145442 | 200 | text/javascript | Script |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | h2 | 247.07100001979 | 316.81800002116 | 89781 | 89476 | 200 | application/javascript | Script |
| https://ncbi.com/Scripts/bootstrap.min.js | h2 | 247.48099999852 | 455.4230000067 | 39985 | 39680 | 200 | application/javascript | Script |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | h2 | 247.70800000988 | 454.7480000183 | 61739 | 61394 | 200 | text/javascript | Script |
| https://ncbi.com/js/polyfill.min.js | h2 | 247.89300002158 | 415.85499999928 | 123509 | 123205 | 200 | application/javascript | Script |
| https://ncbi.com/css/style.css | h2 | 248.20000000182 | 316.27400001162 | 7799 | 7510 | 200 | text/css | Stylesheet |
| https://ncbi.com/chalk-index.css | h2 | 248.56600002386 | 377.15300000855 | 308288 | 307996 | 200 | text/css | Stylesheet |
| https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css | h2 | 248.87200002559 | 263.41800001683 | 6644 | 31000 | 200 | text/css | Stylesheet |
| https://kit.fontawesome.com/b0ffa4f9aa.js | h2 | 249.13599999854 | 297.6380000182 | 4634 | 11025 | 200 | text/javascript | Script |
| https://ncbi.com/Content/Association%20Rollcall.jpg | h2 | 441.50900002569 | 489.52000000281 | 28158 | 27865 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/logos2020.jpg | h2 | 441.83799999882 | 470.70600002189 | 104023 | 103729 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/ia_logos.jpg | h2 | 442.00700000511 | 471.49200001149 | 77103 | 76810 | 200 | image/jpeg | Image |
| https://ncbi.com/js/main.js | h2 | 441.03900002665 | 494.01000002399 | 1921 | 1618 | 200 | application/javascript | Script |
| https://ncbi.com/js/main2.js | h2 | 441.30100001348 | 494.40600001253 | 1927 | 1623 | 200 | application/javascript | Script |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free.min.css?token=b0ffa4f9aa | h2 | 557.93700000504 | 578.90500000212 | 13949 | 60312 | 200 | text/css | Fetch |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free-v4-shims.min.css?token=b0ffa4f9aa | h2 | 558.27000000863 | 572.19800000894 | 5234 | 26682 | 200 | text/css | Fetch |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free-v4-font-face.min.css?token=b0ffa4f9aa | h2 | 558.66999999853 | 579.49000000372 | 1851 | 2956 | 200 | text/css | Fetch |
| https://ncbi.com/Content/callers1.jpg | h2 | 564.38500000513 | 637.95699999901 | 173400 | 173106 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/logo.png | h2 | 564.54400002258 | 590.64600002603 | 14536 | 14244 | 200 | image/png | Image |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-solid-900.woff2 | h2 | 644.83900001505 | 669.35400001239 | 79244 | 78168 | 200 | font/woff2 | Font |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-regular-400.woff2 | h2 | 645.06400001119 | 655.69100002176 | 14293 | 13216 | 200 | font/woff2 | Font |
Network Round Trip Times — 0 ms High Network RTT (Round Trip Times) can have a large impact on performance. Providing servers geographically closer to the user could improve performance.
Server Backend Latencies — 0 ms High server latencies indicate the server is overloaded or has a poor backend performance.
Tasks Below is a list of the top-level main thread tasks that executed during page load.
| Start Time (Ms) | End Time (Ms) |
|---|---|
| 242.351 | 15.58 |
| 405.126 | 29.088 |
| 435.866 | 8.084 |
| 469.398 | 10.344 |
| 481.752 | 79.436 |
| 561.198 | 19.589 |
| 585.252 | 18.133 |
| 612.362 | 13.116 |
| 628.229 | 9.117 |
| 639.7 | 22.837 |
| 671.269 | 13.474 |
| 684.82 | 9.811 |
Script Treemap Data Provide as required, for treemap app.
Other
Defer offscreen images Time to Interactive can be slowed down by resources on the page. Ncbi.com should consider lazy-loading offscreen and hidden images.
Minify CSS — Potential savings of 87 KiB Cascading Style Sheets (CSS) files can contribute to network payload sizes. Ncbi.com should consider minifying CSS files.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 308288 | 79028 |
| https://ncbi.com/Site.css | 17638 | 7425 |
| https://ncbi.com/css/style.css | 7799 | 2157 |
Minify JavaScript — Potential savings of 25 KiB JavaScript (JS) files can contribute to network payload sizes and increase script parse times. Ncbi.com should consider minifying JS files.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/js/polyfill.min.js | 123509 | 25838 |
Efficiently encode images — Potential savings of 30 KiB Unoptimized images can consume more cellular data than what is necessary.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/logos2020.jpg | 103729 | 18523 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 12594 |
Preconnect to required origins Resource hints, such as 'preconnect' or 'dns-prefetch', may assist in establishing early connections to important third-party origins.
Initial server response time was short — Root document took 170 ms It is advised to keep the server response time short for the main document, because all other requests depend on it.
| URL | Time Spent (Ms) |
|---|---|
| https://ncbi.com/ | 169.34 |
Avoid multiple page redirects — Potential savings of 190 ms Redirects can cause additional delays before the page can begin loading. Ncbi.com should avoid multiple or unnecessary page redirects.
| URL | Time Spent (Ms) |
|---|---|
| http://ncbi.com/ | 190 |
| https://ncbi.com/ | 0 |
Preload key requests Key requests can be preloaded by using '<link rel=preload>'. Ncbi.com should consider using '<link rel=preload>' to prioritize fetching resources that are currently requested later in page load.
Use video formats for animated content Large GIFs are inefficient for delivering animated content. It is recommended to use MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF.
Remove duplicate modules in JavaScript bundles Ensure that no duplicate JavaScript modules from bundles exist to reduce bytes consumed by network activity.
Avoid serving legacy JavaScript to modern browsers Polyfills and transforms enable legacy browsers to use new JavaScript features. For bundled JavaScript it is recommended to adopt a modern script deployment strategy using module/nomodule feature detection. This will reduce the amount of code shipped to modern browsers.
Preload Largest Contentful Paint image It is recommended to preload images used by LCP elements, to improve LCP time.
| URL | Potential Savings (Ms) |
|---|---|
| https://ncbi.com/Content/callers1.jpg | 0 |
Avoids enormous network payloads — Total size was 1,444 KiB Large network payloads can cost users money and are linked to long load times.
| URL | Transfer Size (Bytes) |
|---|---|
| https://ncbi.com/chalk-index.css | 308288 |
| https://ncbi.com/Content/callers1.jpg | 173400 |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145788 |
| https://ncbi.com/js/polyfill.min.js | 123509 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 |
| https://ncbi.com/Content/logos2020.jpg | 104023 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89781 |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-solid-900.woff2 | 79244 |
| https://ncbi.com/Content/ia_logos.jpg | 77103 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61739 |
Avoids an excessive DOM size — 335 elements A large DOM (Document Object Model) will increase memory usage, cause longer system calculations as well as costly layout reflows.
| Statistic | Element | Value |
|---|---|---|
| Total DOM Elements | 335 | |
| Maximum DOM Depth | 14 | |
| Maximum Child Elements | 19 |
Avoid chaining critical requests — 16 chains found Below is a list of Critical Request Chains, which shows which resources are loaded with a high priority. Ncbi.com should consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
User Timing marks and measures Make use of the User Timing API to measure an app's real-world performance during key user experiences.
JavaScript execution time — 0.0 s JavaScript (JS) execution time can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
| URL | Total CPU Time (Ms) | Script Evaluation (Ms) | Script Parse (Ms) |
|---|---|---|---|
| https://ncbi.com/ | 139.713 | 6.345 | 2.019 |
Minimizes main-thread work — 0.3 s Main-thread work timing can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
| Category | Time Spent (Ms) |
|---|---|
| Script Evaluation | 114.118 |
| Style & Layout | 76.567 |
| Other | 55.058 |
| Parse HTML & CSS | 26.584 |
| Rendering | 20.262 |
| Script Parsing & Compilation | 11.534 |
All text remains visible during webfont loads Make use of the font-display CSS feature, which will ensure text is user-visible while webfonts are loading.
Keep request counts low and transfer sizes small — 26 requests • 1,444 KiB It is advised to add a budgets.json file in order to set budgets for the quantity and size of page resources.
| Resource Type | Requests | Transfer Size (Bytes) |
|---|---|---|
| Total | 26 | 1479043 |
| Script | 9 | 480724 |
| Stylesheet | 5 | 461513 |
| Image | 5 | 397220 |
| Font | 2 | 93537 |
| Document | 1 | 24697 |
| Other | 4 | 21352 |
| Media | 0 | 0 |
| Third-party | 7 | 125849 |
Minimize third-party usage — Third-party code blocked the main thread for 0 ms It is advised to either limit, remove or delay the loading of redundant third-party code which may be significantly impacting load performance.
| Third-Party | Transfer Size (Bytes) | Main-Thread Blocking Time (Ms) |
|---|---|---|
| 119205 | 0 | |
| 6644 | 0 |
Lazy load third-party resources with facades Consider replacing third-party embeds with a facade until they are required (use lazy loading).
Largest Contentful Paint element — 1 element found The element which was identified as the Largest Contentful Paint.
| Element |
|---|
Largest Contentful Paint image was not lazily loaded Above-the-fold images that are lazily loaded render later in the page lifecycle, which can delay the largest contentful paint.
| Element |
|---|
Avoid large layout shifts — 3 elements found Below is a list of all DOM elements that contribute to the CLS of the page.
| Element | CLS Contribution |
|---|---|
| 2.160231153139E-5 | |
| 1.7063304439191E-5 | |
| 1.3364854215918E-5 |
Uses passive listeners to improve scrolling performance Improve the page's scroll performance by marking touch and wheel event listeners as 'passive'.
Avoids `document.write()` Avoid or limit the use of external scripts that are dynamically injected via 'document.write()' as users on slow connections will be delayed by tens of seconds.
Avoid long main-thread tasks — 1 long task found Below is a list of the longest tasks on the main thread, which is useful when identifying the worst input delay contributors.
| URL | Start Time (Ms) | Duration (Ms) |
|---|---|---|
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 1460 | 79 |
Avoid non-composited animations It is recommended to avoid non-composited animations which are often janky and increase CLS.
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Budgets
Performance budget It is advised to keep the quantity and size of all network requests under the targets set by the provided performance budget.
Timing budget It is advised to set a timing budget to monitor the performance of your site.
Metrics
First Contentful Paint — 1.5 s The time taken for the first image or text on the page to be rendered.
Speed Index — 1.5 s The time taken for the page contents to be visibly populated.
Largest Contentful Paint — 1.8 s The timing of the largest text or image that is painted.
Audits
First Meaningful Paint — 1.5 s The time taken for the primary content of the page to be rendered.
Other
Eliminate render-blocking resources — Potential savings of 540 ms Resources, such as JavaScript and style sheets, can block the first paint of the page. Ncbi.com should consider delivering critical JavaScript/style sheets (JS/CSS) inline and deferring all non-critical JS/CSS.
| URL | Transfer Size (Bytes) | Potential Savings (Ms) |
|---|---|---|
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 | 280 |
| https://ncbi.com/chalk-index.css | 308288 | 240 |
| https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css | 6644 | 230 |
Properly size images — Potential savings of 169 KiB Images can slow down the page's load time. Ncbi.com should consider serving more appropriate-sized images.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/logos2020.jpg | 103729 | 91785 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 67909 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 27865 | 13448 |
Reduce unused CSS — Potential savings of 441 KiB Dead and/or unused rules in Style Sheets (CSS) can contribute to network payload sizes. Ncbi.com should consider removing dead rules from style sheets and deferring the loading of CSS not used for above-the-fold content.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 308288 | 308288 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 | 116702 |
| https://ncbi.com/Site.css | 17638 | 14451 |
| /*!
* Font Awesome Free 5.15.4 by @fontawesome - https://fontawesome.com
* License - https://fonta... | 12320 | 12222 |
Reduce unused JavaScript — Potential savings of 304 KiB It is advised to remove unused JavaScript in order to reduce bytes consumed by network activity.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145788 | 103590 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89781 | 60826 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61739 | 57523 |
| https://ncbi.com/js/polyfill.min.js | 123509 | 56668 |
| https://ncbi.com/Scripts/bootstrap.min.js | 39985 | 32625 |
Serve images in next-gen formats — Potential savings of 234 KiB Consider JPEG 2000, JPEG XR or WebP image formats which provide better compression than PNG and JPEG.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/callers1.jpg | 173106 | 101941.7 |
| https://ncbi.com/Content/logos2020.jpg | 103729 | 67836.3 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 49988 |
| https://ncbi.com/Content/logo.png | 14244 | 10745.75 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 27865 | 9296.95 |
Enable text compression — Potential savings of 728 KiB Text-based resources should be served with compression, such as gzip, deflate or brotli.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 307996 | 268402 |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145442 | 110467 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 120805 | 101119 |
| https://ncbi.com/js/polyfill.min.js | 123205 | 86854 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89476 | 58526 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61394 | 45760 |
| https://ncbi.com/Scripts/bootstrap.min.js | 39680 | 28740 |
| https://ncbi.com/ | 24381 | 17864 |
| https://ncbi.com/Site.css | 17348 | 14787 |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | 11095 | 6592 |
| https://ncbi.com/css/style.css | 7510 | 5997 |
Other
Serve static assets with an efficient cache policy — 13 resources found Ncbi.com can speed up repeat visits by increasing the cache lifetime, which is essentially how long before a cached copy expires.
| URL | Cache TTL (Ms) | Transfer Size (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 0 | 308288 |
| https://ncbi.com/Content/callers1.jpg | 0 | 173400 |
| https://ncbi.com/js/polyfill.min.js | 0 | 123509 |
| https://ncbi.com/Content/logos2020.jpg | 0 | 104023 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 0 | 89781 |
| https://ncbi.com/Content/ia_logos.jpg | 0 | 77103 |
| https://ncbi.com/Scripts/bootstrap.min.js | 0 | 39985 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 0 | 28158 |
| https://ncbi.com/Site.css | 0 | 17638 |
| https://ncbi.com/Content/logo.png | 0 | 14536 |
| https://ncbi.com/css/style.css | 0 | 7799 |
| https://ncbi.com/js/main2.js | 0 | 1927 |
| https://ncbi.com/js/main.js | 0 | 1921 |
Image elements do not have explicit `width` and `height` Reduce layout shifts and improve CLS by setting explicit width and height properties on image elements.
| URL |
|---|
| https://ncbi.com/Content/logos2020.jpg |
| https://ncbi.com/Content/ia_logos.jpg |
| https://ncbi.com/Content/Association%20Rollcall.jpg |
Registers an `unload` listener The 'unload' event does not fire reliably, causing issues with browser optimizations such as the Back-Forward Cache. It is recommended that 'pagehide' or 'visibilitychange' events are used instead.
| Source |
|---|
Accessibility
Indicates how accessible the page is and highlights opportunities where the page can be made more accessible to users of ncbi.com. This includes details about various page attributes that can be optimized.Navigation
`[accesskey]` values are unique Access keys assist users with focusing on different parts of the page. Each access key should be unique for proper navigation.
The page contains a heading, skip link, or landmark region It is advised to provide ways to bypass repetitive content, allowing users to navigate the page efficiently.
`[id]` attributes on active, focusable elements are unique Ensure all focusable elements have a unique id value to allow them to be visible to users of assistive technologies, like a screen reader.
Heading elements appear in a sequentially-descending order Properly order all headers and do not skip heading levels to better the navigation and readability for users of assistive technologies, like a screen reader.
No element has a `[tabindex]` value greater than 0 Although technically valid, a tabindex value greater than 0 often creates frustrating experiences for users who rely on assistive technologies.
ARIA
`[aria-*]` attributes match their roles Avoid mismatching 'aria-*' attributes and their 'role' value, as it invalidates the attribute.
`button`, `link`, and `menuitem` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-hidden="true"]` is not present on the document `<body>` If aria-hidden=true is set on the document body, assistive technologies, like a screen reader will work inconsistently.
`[aria-hidden="true"]` elements do not contain focusable descendents Interactive elements within an aria-hidden=true element are unavailable to users of assistive technologies, like a screen reader.
ARIA input fields have accessible names Generic names are announced to users of assistive technologies, like a screen reader, when an input field does not have an accessible name specified.
ARIA `meter` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `progressbar` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[role]`s have all required `[aria-*]` attributes Some ARIA roles have required 'aria-*' attributes, which provide essential information about state and functionality.
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children. Some ARIA parent roles cannot perform their intended functions if specific child roles are not used.
`[role]`s are contained by their required parent element Some ARIA child roles cannot perform their intended functions if specific parent roles are not used.
`[role]` values are valid All ARIA roles require valid values to perform their intended functions.
ARIA toggle fields have accessible names Generic names are announced to users of assistive technologies, like a screen reader, when a toggle field does not have an accessible name specified.
ARIA `tooltip` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `treeitem` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-*]` attributes have valid values ARIA attributes cannot be interpreted with invalid values when used by screen readers and other assistive technologies.
`[aria-*]` attributes are valid and not misspelled ARIA attributes cannot be interpreted with invalid names when used by screen readers and other assistive technologies.
ARIA IDs are unique Ensure all ARIA ID values are unique to prevent elements from being overlooked by assistive technologies, like a screen reader.
Names and labels
Buttons have an accessible name Buttons become unusable as they are announced simply as "button" when the button does not have an accessible name, when used by screen readers and other assistive technologies.
Document has a `<title>` element Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
No form fields have multiple labels Having multiple labels for form fields can be confusing to assistive technologies, like a screen reader.
`<frame>` or `<iframe>` elements have a title Screen reader users and other assistive technology users rely on frame titles to describe the contents of frames.
`<input type="image">` elements have `[alt]` text Input buttons with alternative text assist screen readers and other assistive technology users to understand its purpose.
Form elements have associated labels Screen readers and other assistive technologies rely on labels to properly announce form controls.
`<object>` elements have alternate text It is advised that alt text is used on '<object>' elements in order to provide meaning to screen reader and other assistive technology users, as these technologies are unable to translate non-text content.
Contrast
Background and foreground colors have a sufficient contrast ratio Many (if not most) users find low-contrast text difficult or impossible to read.
Tables and lists
`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements. Screen readers and other assistive technologies may produce poor and inaccurate output when definition lists are not properly marked up.
Definition list items are wrapped in `<dl>` elements In order for screen readers and other assistive technologies to properly announce definition list items ('<dt>' and '<dd>'), they must be wrapped in parent a '<dl>' element.
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`). Use proper list structure to aid screen readers and other assistive technologies.
List items (`<li>`) are contained within `<ul>` or `<ol>` parent elements In order for screen readers to announce list items, ensure that list items ('<li>') are contained within parent '<ul>' or '<ol>' tags.
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table. Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that '<td>' cells using the headers attribute only refer to other cells in the same table, to improve screen reader user experience.
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe. Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that table headers refer to some set of cells, to improve screen reader user experience.
Internationalization and localization
`<html>` element has a `[lang]` attribute It is advised to provide a lang attribute so that screen readers and other assistive technologies are guaranteed to announce the page's text correctly. When not provided, the user's default language setting will be used which may cause inaccuracies.
`<html>` element has a valid value for its `[lang]` attribute Specify a valid BCP 47 language in order to help screen readers and other assistive technologies announce text properly.
`[lang]` attributes have a valid value Specify a valid BCP 47 language on elements in order to help screen readers and other assistive technologies announce text properly.
Best practices
The document does not use `<meta http-equiv="refresh">` Pages that refresh automatically cause a poor user experience as focus is directed back to the top of the page unexpectedly.
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5. For users with low vision who rely on screen magnification, ensure that zooming is not disabled.
Audio and video
`<video>` elements contain a `<track>` element with `[kind="captions"]` Ncbi.com may provide assistance to deaf or hearing-impaired users with captions on videos.
Names and labels
Image elements do not have `[alt]` attributes Provide short and descriptive alternative text where possible on informative elements.
| Failing Elements |
|---|
Links do not have a discernible name In order to improve the navigation for screen reader and other assistive technology users, use link text that is unique, focusable and discernible.
| Failing Elements |
|---|
Manual Checks
The page has a logical tab order The visual layout should be logical in its tab order and users cannot focus elements that are offscreen.
Interactive controls are keyboard focusable Ensure that custom interactive controls are keyboard focusable and that a focus indicator is displayed.
Interactive elements indicate their purpose and state Ensure that interactive elements (such as links and buttons) are distinguishable from non-interactive elements and that they indicate their state.
The user's focus is directed to new content added to the page When new content (such as a dialogue) is added to the page, the user's focus should be directed to it.
User focus is not accidentally trapped in a region Avoid focus being accidentally trapped when a user tabs in and out of controls or regions on page.
Custom controls have associated labels Ensure that custom interactive controls have associated labels, which are provided by aria-label and aria-labelledby attributes.
Custom controls have ARIA roles Ensure that all custom interactive controls have appropriate ARIA roles.
Visual order on the page follows DOM order Ensure that the DOM order matches with the page's visual order, in order to improve navigation for screen readers and other assistive technologies.
Offscreen content is hidden from assistive technology Ensure that offscreen content is hidden through the use of "display:none" styling or the aria-hidden attribute.
HTML5 landmark elements are used to improve navigation Elements such as <main> and <nav> are recommended as they are used by screen readers and other assistive technologies to improve keyboard navigation.
Best Practices
Indicates the recommended, best practices currently in place on the page and highlights the best practices that ncbi.com should incorporate. This includes practices such as protecting pages with HTTPS.Audits
Avoids requesting the geolocation permission on page load When requesting a user's location, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids requesting the notification permission on page load When requesting permission to send notifications, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids front-end JavaScript libraries with known security vulnerabilities Ensure that the use of third-party scripts is minimal and that only trusted third-party scripts are used as some may contain known security vulnerabilities which may be exploited by attackers.
Ensure CSP is effective against XSS attacks Significantly reduce the risk of cross-site scripting attacks (XSS) by ensuring you have a strong Content Security Policy (CSP).
| Description | Directive | Severity |
|---|---|---|
| No CSP found in enforcement mode | High |
Audits
Allows users to paste into password fields Ensure that password inputs may be pasted into to aid in the user's ability to use password managers and improve security.
Displays images with correct aspect ratio Ensure that image display dimensions match their natural aspect ratio.
Serves images with appropriate resolution For maximum image clarity, ensure images have natural dimensions and are proportional to the display size and pixel ratio.
Fonts with `font-display: optional` are preloaded It is recommended that optional fonts are preloaded.
Audits
Page has the HTML doctype Ensure a doctype is specified to prevent the browser from switching to quirks-mode.
Properly defines charset It is advised to declare a character encoding, optionally via a <meta> tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header.
Audits
Detected JavaScript libraries Below is a list of all front-end JavaScript libraries that were detected on the page.
| Name | Version |
|---|---|
| Bootstrap | 3.4.1 |
| jQuery | 3.5.1 |
| Modernizr | 2.8.3 |
| core-js | core-js-global@2.6.5 |
Avoids deprecated APIs Avoid deprecated APIs which will eventually be removed the browser.
No browser errors logged to the console Below is a list of all errors logged to the console, which indicate unresolved problems on the site.
Page has valid source maps Consider deploying source maps for added benefits such as the ability to debug while in production.
No issues in the `Issues` panel in Chrome Devtools There may be unresolved issues logged to Chrome Devtools.
Audits
Does not use HTTPS — 1 insecure request found Ensure that all pages are protected with HTTPS (including those that do not handle sensitive data) as HTTPS prevents tampering and passive listening on communications between the app and its users. Additionally, HTTPS is a prerequisite for HTTP/2 and many new web platform APIs.
| Insecure URL | Request Resolution |
|---|---|
| http://ncbi.com/ | Allowed |
SEO
Indicates how well the page is optimized for ranking in search engines and highlights Search Engine Optimization (SEO) opportunities for ncbi.com. This includes optimizations such as providing meta data.Mobile Friendly
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Document uses legible font sizes Font sizes of 12px or less are too small to most mobile users without user gestures and further action. Aim for more than 60% of page text to use font sizes greater than 12px.
Tap targets are sized appropriately Interactive elements (such as buttons and links) should be appropriately spaced, sized and easy enough to select or tap with regard to their surrounding elements.
Content Best Practices
Document has a `<title>` element Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
Links have descriptive text Make use of descriptive link text to assist search engines in understanding the content.
Document has a valid `hreflang` Search engines can be instructed to list specific versions of a page for a given language or region through the use of hreflang links.
Document has a valid `rel=canonical` Search engines can be suggested which URL should be shown in search results through the use of canonical links.
Document avoids plugins The content of plugins cannot be indexed by search engines and many devices either restrict or do not support them.
Crawling and Indexing
Page has successful HTTP status code Avoid pages with unsuccessful HTTP status codes as they may not be indexed by search engines.
Page isn’t blocked from indexing Pages that cannot be crawled by search engines cannot be indexed or included in their search results. Ensure that search engines have permission to crawl all pages that should be indexed.
robots.txt is valid Malformed robots.txt files prevent crawlers from understanding how a site wants to be crawled or indexed, which can be devastating to SEO.
Content Best Practices
Document does not have a meta description Meta descriptions may be used by search engines when displaying a link to the page and should concisely summarize the page's content.
Image elements do not have `[alt]` attributes Provide short and descriptive alternative text where possible on informative elements.
| Failing Elements |
|---|
Crawling and Indexing
Links are not crawlable Ensure that the 'href' attribute of anchor elements links to the appropriate destination. This allows for more pages of the site to be discovered by search engines.
| Uncrawlable Link |
|---|
Manual Checks
Structured data is valid Structured data can be validated through the use of the Structured Data Testing Tool and the Structured Data Linter.
PWA
Indicates how valid the aspects of a Progressive Web App (PWA) are for the page and highlights opportunities to enable/improve the PWA of ncbi.com. This includes details about web app manifests.PWA Optimized
Content is sized correctly for the viewport Ensure that the width of the app's content matches the width of the viewport, otherwise the app might not be optimized for mobile screens.
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Installable
Web app manifest or service worker do not meet the installability requirements — 1 reason User engagement may be increased by leveraging the browsers ability to proactively prompt users to add the app to their homescreen.
| Failure reason |
|---|
| No manifest was fetched |
PWA Optimized
Does not register a service worker that controls page and `start_url` A service worker is used to provide Progressive Web Apps the use of features such as working offline, the ability for the app to be added to the homescreen as well as push notifications.
Is not configured for a custom splash screen Themed splash screens ensure a high-quality user experience at launch for app users.
View Data
Does not set a theme color for the address bar. A theme may be applied to the browser address bar, which ideally can be made to match the site.
View Data
Does not provide a valid `apple-touch-icon` iOS users of Progressive Web Apps will benefit from an apple touch icon, which can be defined with 'apple-touch-icon', which must point to a non-transparent 192px (or 180px) square PNG.
Manifest doesn't have a maskable icon Maskable icons are great to ensure that images fill the entire shape when installing the app on a device.
Manual Checks
Site works cross-browser Ensure that the Progressive Web App works correctly across every major browser.
Page transitions don't feel like they block on the network Users perceive apps with responsive, snappy transitions as higher peforming and ensures a great user experience, even on a slow network.
Each page has a URL Ensure that all pages are deep linkable via URL. They should also be unique for the purpose of shareability on social media.
Avg. (All Categories)
Performance
Accessibility
Best Practices
SEO
PWA
0–49 (Fail) 50–89 (Average) 90–100 (Pass)
URL: https://ncbi.com/
Updated: 13th January, 2023
Simulate loading on mobile
Performance
Indicates how well the page is performing and highlights opportunities where performance may be improved for ncbi.com. This includes details about optimizing page load times which can result in a better user experience.Metrics
Total Blocking Time — 150 ms The total blocking time is the sum of all time periods between First Contentful Paint and Time to Interactive (when task length exceeded 50ms).
Cumulative Layout Shift — 0 Cumulative Layout Shift is the measurement of visible elements collective movement within the viewport.
View Data
Other
Defer offscreen images Time to Interactive can be slowed down by resources on the page. Ncbi.com should consider lazy-loading offscreen and hidden images.
Minify JavaScript — Potential savings of 25 KiB JavaScript (JS) files can contribute to network payload sizes and increase script parse times. Ncbi.com should consider minifying JS files.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/js/polyfill.min.js | 123509 | 25838 |
Preconnect to required origins Resource hints, such as 'preconnect' or 'dns-prefetch', may assist in establishing early connections to important third-party origins.
Initial server response time was short — Root document took 200 ms It is advised to keep the server response time short for the main document, because all other requests depend on it.
| URL | Time Spent (Ms) |
|---|---|
| https://ncbi.com/ | 198.171 |
Avoid multiple page redirects — Potential savings of 630 ms Redirects can cause additional delays before the page can begin loading. Ncbi.com should avoid multiple or unnecessary page redirects.
| URL | Time Spent (Ms) |
|---|---|
| http://ncbi.com/ | 630 |
| https://ncbi.com/ | 0 |
Preload key requests Key requests can be preloaded by using '<link rel=preload>'. Ncbi.com should consider using '<link rel=preload>' to prioritize fetching resources that are currently requested later in page load.
Use video formats for animated content Large GIFs are inefficient for delivering animated content. It is recommended to use MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF.
Remove duplicate modules in JavaScript bundles Ensure that no duplicate JavaScript modules from bundles exist to reduce bytes consumed by network activity.
Avoid serving legacy JavaScript to modern browsers Polyfills and transforms enable legacy browsers to use new JavaScript features. For bundled JavaScript it is recommended to adopt a modern script deployment strategy using module/nomodule feature detection. This will reduce the amount of code shipped to modern browsers.
Preload Largest Contentful Paint image It is recommended to preload images used by LCP elements, to improve LCP time.
| URL | Potential Savings (Ms) |
|---|---|
| https://ncbi.com/Content/callers_small.jpg | 0 |
Avoids enormous network payloads — Total size was 1,321 KiB Large network payloads can cost users money and are linked to long load times.
| URL | Transfer Size (Bytes) |
|---|---|
| https://ncbi.com/chalk-index.css | 308288 |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145788 |
| https://ncbi.com/js/polyfill.min.js | 123509 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 |
| https://ncbi.com/Content/logos2020.jpg | 104023 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89781 |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-solid-900.woff2 | 79233 |
| https://ncbi.com/Content/ia_logos.jpg | 77103 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61739 |
| https://ncbi.com/Content/callers_small.jpg | 47515 |
Avoids an excessive DOM size — 335 elements A large DOM (Document Object Model) will increase memory usage, cause longer system calculations as well as costly layout reflows.
| Statistic | Element | Value |
|---|---|---|
| Total DOM Elements | 335 | |
| Maximum DOM Depth | 14 | |
| Maximum Child Elements | 19 |
Avoid chaining critical requests — 14 chains found Below is a list of Critical Request Chains, which shows which resources are loaded with a high priority. Ncbi.com should consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
User Timing marks and measures Make use of the User Timing API to measure an app's real-world performance during key user experiences.
JavaScript execution time — 0.5 s JavaScript (JS) execution time can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
| URL | Total CPU Time (Ms) | Script Evaluation (Ms) | Script Parse (Ms) |
|---|---|---|---|
| https://ncbi.com/ | 741.196 | 33.028 | 6.664 |
| https://ncbi.com/js/polyfill.min.js | 184.4 | 175.172 | 9.228 |
| Unattributable | 157.964 | 11.8 | 0 |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | 122.728 | 90.12 | 1.584 |
| https://kit.fontawesome.com/b0ffa4f9aa.js | 92.636 | 81.412 | 1.212 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 86.912 | 73.636 | 9.472 |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 55.624 | 35.62 | 15.164 |
Minimizes main-thread work — 1.5 s Main-thread work timing can be lowered by reducing the time required for parsing, compiling and executing JS. Delivering smaller JS payloads may help with this.
| Category | Time Spent (Ms) |
|---|---|
| Style & Layout | 525.588 |
| Script Evaluation | 519.656 |
| Other | 236.892 |
| Parse HTML & CSS | 108.448 |
| Rendering | 53.128 |
| Script Parsing & Compilation | 52.336 |
All text remains visible during webfont loads Make use of the font-display CSS feature, which will ensure text is user-visible while webfonts are loading.
Keep request counts low and transfer sizes small — 26 requests • 1,321 KiB It is advised to add a budgets.json file in order to set budgets for the quantity and size of page resources.
| Resource Type | Requests | Transfer Size (Bytes) |
|---|---|---|
| Total | 26 | 1353143 |
| Script | 9 | 480724 |
| Stylesheet | 5 | 461510 |
| Image | 5 | 271335 |
| Font | 2 | 93529 |
| Document | 1 | 24697 |
| Other | 4 | 21348 |
| Media | 0 | 0 |
| Third-party | 7 | 125834 |
Minimize third-party usage — Third-party code blocked the main thread for 10 ms It is advised to either limit, remove or delay the loading of redundant third-party code which may be significantly impacting load performance.
| Third-Party | Transfer Size (Bytes) | Main-Thread Blocking Time (Ms) |
|---|---|---|
| 119193 | 12.68 | |
| 6641 | 0 |
Lazy load third-party resources with facades Consider replacing third-party embeds with a facade until they are required (use lazy loading).
Largest Contentful Paint element — 1 element found The element which was identified as the Largest Contentful Paint.
| Element |
|---|
Largest Contentful Paint image was not lazily loaded Above-the-fold images that are lazily loaded render later in the page lifecycle, which can delay the largest contentful paint.
| Element |
|---|
Avoid large layout shifts — 1 element found Below is a list of all DOM elements that contribute to the CLS of the page.
| Element | CLS Contribution |
|---|---|
| 5.82275390625E-5 |
Uses passive listeners to improve scrolling performance Improve the page's scroll performance by marking touch and wheel event listeners as 'passive'.
Avoids `document.write()` Avoid or limit the use of external scripts that are dynamically injected via 'document.write()' as users on slow connections will be delayed by tens of seconds.
Avoid long main-thread tasks — 7 long tasks found Below is a list of the longest tasks on the main thread, which is useful when identifying the worst input delay contributors.
| URL | Start Time (Ms) | Duration (Ms) |
|---|---|---|
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 6810 | 403 |
| https://ncbi.com/ | 1410 | 102 |
| https://ncbi.com/ | 1260 | 76 |
| https://ncbi.com/ | 1336 | 74 |
| https://kit.fontawesome.com/b0ffa4f9aa.js | 2116 | 64 |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | 4260 | 61 |
| https://ncbi.com/ | 1542 | 54 |
Avoid non-composited animations It is recommended to avoid non-composited animations which are often janky and increase CLS.
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Budgets
Performance budget It is advised to keep the quantity and size of all network requests under the targets set by the provided performance budget.
Timing budget It is advised to set a timing budget to monitor the performance of your site.
Audits
Network Requests Below is a list of network requests that were made during page load.
| URL | Protocol | Start Time (Ms) | End Time (Ms) | Transfer Size (Bytes) | Resource Size (Bytes) | Status Code | MIME Type | Resource Type |
|---|---|---|---|---|---|---|---|---|
| http://ncbi.com/ | http/1.1 | 0 | 87.236999999732 | 318 | 0 | 301 | text/html | |
| https://ncbi.com/ | h2 | 87.617000099272 | 284.79700023308 | 24697 | 24381 | 200 | text/html | Document |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | h2 | 298.67399996147 | 451.12900016829 | 11440 | 11095 | 200 | text/javascript | Script |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | h2 | 300.45400001109 | 540.93499993905 | 121144 | 120805 | 200 | text/css | Stylesheet |
| https://ncbi.com/Site.css | h2 | 300.62700016424 | 451.49100013077 | 17638 | 17348 | 200 | text/css | Stylesheet |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | h2 | 300.79999985173 | 534.10700010136 | 145788 | 145442 | 200 | text/javascript | Script |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | h2 | 308.71600005776 | 492.41199996322 | 89781 | 89476 | 200 | application/javascript | Script |
| https://ncbi.com/Scripts/bootstrap.min.js | h2 | 308.86999983341 | 418.77799993381 | 39985 | 39680 | 200 | application/javascript | Script |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | h2 | 308.97899996489 | 531.73500020057 | 61739 | 61394 | 200 | text/javascript | Script |
| https://ncbi.com/js/polyfill.min.js | h2 | 309.328999836 | 398.42500025406 | 123509 | 123205 | 200 | application/javascript | Script |
| https://ncbi.com/css/style.css | h2 | 309.41999983042 | 470.55099997669 | 7799 | 7510 | 200 | text/css | Stylesheet |
| https://ncbi.com/chalk-index.css | h2 | 309.51400008053 | 448.6630000174 | 308288 | 307996 | 200 | text/css | Stylesheet |
| https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css | h2 | 309.59700001404 | 332.26099982858 | 6641 | 31000 | 200 | text/css | Stylesheet |
| https://kit.fontawesome.com/b0ffa4f9aa.js | h2 | 309.68599999323 | 352.57099987939 | 4634 | 11025 | 200 | text/javascript | Script |
| https://ncbi.com/Content/Association%20Rollcall.jpg | h2 | 489.44800021127 | 560.52300008014 | 28158 | 27865 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/logos2020.jpg | h2 | 489.70500007272 | 559.89800021052 | 104023 | 103729 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/ia_logos.jpg | h2 | 489.80699991807 | 536.85799986124 | 77103 | 76810 | 200 | image/jpeg | Image |
| https://ncbi.com/js/main.js | h2 | 489.03300007805 | 617.91800009087 | 1921 | 1618 | 200 | application/javascript | Script |
| https://ncbi.com/js/main2.js | h2 | 489.21900009736 | 556.76299985498 | 1927 | 1623 | 200 | application/javascript | Script |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free.min.css?token=b0ffa4f9aa | h2 | 649.79699999094 | 678.19599993527 | 13946 | 60312 | 200 | text/css | Fetch |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free-v4-shims.min.css?token=b0ffa4f9aa | h2 | 649.96400009841 | 716.67699981481 | 5228 | 26682 | 200 | text/css | Fetch |
| https://ka-f.fontawesome.com/releases/v5.15.4/css/free-v4-font-face.min.css?token=b0ffa4f9aa | h2 | 650.59900004417 | 672.7030002512 | 1856 | 2956 | 200 | text/css | Fetch |
| https://ncbi.com/Content/callers_small.jpg | h2 | 658.47899997607 | 684.70800016075 | 47515 | 47222 | 200 | image/jpeg | Image |
| https://ncbi.com/Content/logo.png | h2 | 658.78600021824 | 683.24699997902 | 14536 | 14244 | 200 | image/png | Image |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-solid-900.woff2 | h2 | 809.23000024632 | 888.90200015157 | 79233 | 78168 | 200 | font/woff2 | Font |
| https://ka-f.fontawesome.com/releases/v5.15.4/webfonts/free-fa-regular-400.woff2 | h2 | 809.36500011012 | 833.15900014713 | 14296 | 13216 | 200 | font/woff2 | Font |
Network Round Trip Times — 0 ms High Network RTT (Round Trip Times) can have a large impact on performance. Providing servers geographically closer to the user could improve performance.
Server Backend Latencies — 0 ms High server latencies indicate the server is overloaded or has a poor backend performance.
Tasks Below is a list of the top-level main thread tasks that executed during page load.
| Start Time (Ms) | End Time (Ms) |
|---|---|
| 291.093 | 19.004 |
| 455.28 | 30.682 |
| 544.937 | 6.677 |
| 552.925 | 100.682 |
| 653.63 | 37.144 |
| 699.187 | 51.177 |
| 756.791 | 14.878 |
| 776.029 | 10.391 |
| 786.767 | 16.024 |
| 804.188 | 26.842 |
| 893.429 | 7.348 |
Script Treemap Data Provide as required, for treemap app.
Other
Properly size images — Potential savings of 82 KiB Images can slow down the page's load time. Ncbi.com should consider serving more appropriate-sized images.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/logos2020.jpg | 103729 | 54166 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 15479 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 27865 | 14236 |
Minify CSS — Potential savings of 87 KiB Cascading Style Sheets (CSS) files can contribute to network payload sizes. Ncbi.com should consider minifying CSS files.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 308288 | 79028 |
| https://ncbi.com/Site.css | 17638 | 7425 |
| https://ncbi.com/css/style.css | 7799 | 2157 |
Efficiently encode images — Potential savings of 37 KiB Unoptimized images can consume more cellular data than what is necessary.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/logos2020.jpg | 103729 | 18523 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 12594 |
| https://ncbi.com/Content/callers_small.jpg | 47222 | 6466 |
Metrics
First Contentful Paint — 7.1 s The time taken for the first image or text on the page to be rendered.
Time to Interactive — 7.4 s The time taken for the page to become fully interactive.
Speed Index — 7.1 s The time taken for the page contents to be visibly populated.
Largest Contentful Paint — 8.1 s The timing of the largest text or image that is painted.
Audits
Max Potential First Input Delay — 400 ms Users could experience a delay when interacting with the page.
First Meaningful Paint — 7.1 s The time taken for the primary content of the page to be rendered.
Other
Eliminate render-blocking resources — Potential savings of 2,880 ms Resources, such as JavaScript and style sheets, can block the first paint of the page. Ncbi.com should consider delivering critical JavaScript/style sheets (JS/CSS) inline and deferring all non-critical JS/CSS.
| URL | Transfer Size (Bytes) | Potential Savings (Ms) |
|---|---|---|
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 | 1350 |
| https://ncbi.com/css/style.css | 7799 | 150 |
| https://ncbi.com/chalk-index.css | 308288 | 1500 |
| https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css | 6641 | 780 |
Reduce unused CSS — Potential savings of 443 KiB Dead and/or unused rules in Style Sheets (CSS) can contribute to network payload sizes. Ncbi.com should consider removing dead rules from style sheets and deferring the loading of CSS not used for above-the-fold content.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 308288 | 308288 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 121144 | 117256 |
| https://ncbi.com/Site.css | 17638 | 16050 |
| /*!
* Font Awesome Free 5.15.4 by @fontawesome - https://fontawesome.com
* License - https://fonta... | 12320 | 12222 |
Reduce unused JavaScript — Potential savings of 305 KiB It is advised to remove unused JavaScript in order to reduce bytes consumed by network activity.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145788 | 104333 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89781 | 60826 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61739 | 57700 |
| https://ncbi.com/js/polyfill.min.js | 123509 | 56668 |
| https://ncbi.com/Scripts/bootstrap.min.js | 39985 | 32625 |
Serve images in next-gen formats — Potential savings of 163 KiB Consider JPEG 2000, JPEG XR or WebP image formats which provide better compression than PNG and JPEG.
| URL | Resource Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/Content/logos2020.jpg | 103729 | 67836.3 |
| https://ncbi.com/Content/ia_logos.jpg | 76810 | 49988 |
| https://ncbi.com/Content/callers_small.jpg | 47222 | 28823.4 |
| https://ncbi.com/Content/logo.png | 14244 | 10745.75 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 27865 | 9296.95 |
Enable text compression — Potential savings of 728 KiB Text-based resources should be served with compression, such as gzip, deflate or brotli.
| URL | Transfer Size (Bytes) | Potential Savings (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 307996 | 268402 |
| https://ncbi.com/bundles/MsAjaxJs?v=D6VN0fHlwFSIWjbVzi6mZyE9Ls-4LNrSSYVGRU46XF81 | 145442 | 110467 |
| https://ncbi.com/Content/css?v=DrsT-Kbel3-9Pud4ZtF8Vs1UlJTfhSTNR6gZmXHYx0U1 | 120805 | 101119 |
| https://ncbi.com/js/polyfill.min.js | 123205 | 86854 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 89476 | 58526 |
| https://ncbi.com/bundles/WebFormsJs?v=N8tymL9KraMLGAMFuPycfH3pXe6uUlRXdhtYv8A_jUU1 | 61394 | 45760 |
| https://ncbi.com/Scripts/bootstrap.min.js | 39680 | 28740 |
| https://ncbi.com/ | 24381 | 17864 |
| https://ncbi.com/Site.css | 17348 | 14787 |
| https://ncbi.com/bundles/modernizr?v=inCVuEFe6J4Q07A0AcRsbJic_UE5MwpRMNGcOtk94TE1 | 11095 | 6592 |
| https://ncbi.com/css/style.css | 7510 | 5997 |
Serve static assets with an efficient cache policy — 13 resources found Ncbi.com can speed up repeat visits by increasing the cache lifetime, which is essentially how long before a cached copy expires.
| URL | Cache TTL (Ms) | Transfer Size (Bytes) |
|---|---|---|
| https://ncbi.com/chalk-index.css | 0 | 308288 |
| https://ncbi.com/js/polyfill.min.js | 0 | 123509 |
| https://ncbi.com/Content/logos2020.jpg | 0 | 104023 |
| https://ncbi.com/Scripts/jquery-3.4.1.min.js | 0 | 89781 |
| https://ncbi.com/Content/ia_logos.jpg | 0 | 77103 |
| https://ncbi.com/Content/callers_small.jpg | 0 | 47515 |
| https://ncbi.com/Scripts/bootstrap.min.js | 0 | 39985 |
| https://ncbi.com/Content/Association%20Rollcall.jpg | 0 | 28158 |
| https://ncbi.com/Site.css | 0 | 17638 |
| https://ncbi.com/Content/logo.png | 0 | 14536 |
| https://ncbi.com/css/style.css | 0 | 7799 |
| https://ncbi.com/js/main2.js | 0 | 1927 |
| https://ncbi.com/js/main.js | 0 | 1921 |
Image elements do not have explicit `width` and `height` Reduce layout shifts and improve CLS by setting explicit width and height properties on image elements.
| URL |
|---|
| https://ncbi.com/Content/logos2020.jpg |
| https://ncbi.com/Content/ia_logos.jpg |
| https://ncbi.com/Content/Association%20Rollcall.jpg |
Registers an `unload` listener The 'unload' event does not fire reliably, causing issues with browser optimizations such as the Back-Forward Cache. It is recommended that 'pagehide' or 'visibilitychange' events are used instead.
| Source |
|---|
First Contentful Paint (3G) — 15463 ms The time taken for the first image or text on the page to be rendered while on a 3G network.
Accessibility
Indicates how accessible the page is and highlights opportunities where the page can be made more accessible to users of ncbi.com. This includes details about various page attributes that can be optimized.Navigation
`[accesskey]` values are unique Access keys assist users with focusing on different parts of the page. Each access key should be unique for proper navigation.
The page contains a heading, skip link, or landmark region It is advised to provide ways to bypass repetitive content, allowing users to navigate the page efficiently.
`[id]` attributes on active, focusable elements are unique Ensure all focusable elements have a unique id value to allow them to be visible to users of assistive technologies, like a screen reader.
Heading elements appear in a sequentially-descending order Properly order all headers and do not skip heading levels to better the navigation and readability for users of assistive technologies, like a screen reader.
No element has a `[tabindex]` value greater than 0 Although technically valid, a tabindex value greater than 0 often creates frustrating experiences for users who rely on assistive technologies.
ARIA
`[aria-*]` attributes match their roles Avoid mismatching 'aria-*' attributes and their 'role' value, as it invalidates the attribute.
`button`, `link`, and `menuitem` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-hidden="true"]` is not present on the document `<body>` If aria-hidden=true is set on the document body, assistive technologies, like a screen reader will work inconsistently.
`[aria-hidden="true"]` elements do not contain focusable descendents Interactive elements within an aria-hidden=true element are unavailable to users of assistive technologies, like a screen reader.
ARIA input fields have accessible names Generic names are announced to users of assistive technologies, like a screen reader, when an input field does not have an accessible name specified.
ARIA `meter` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `progressbar` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[role]`s have all required `[aria-*]` attributes Some ARIA roles have required 'aria-*' attributes, which provide essential information about state and functionality.
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children. Some ARIA parent roles cannot perform their intended functions if specific child roles are not used.
`[role]`s are contained by their required parent element Some ARIA child roles cannot perform their intended functions if specific parent roles are not used.
`[role]` values are valid All ARIA roles require valid values to perform their intended functions.
ARIA toggle fields have accessible names Generic names are announced to users of assistive technologies, like a screen reader, when a toggle field does not have an accessible name specified.
ARIA `tooltip` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
ARIA `treeitem` elements have accessible names Without accessible names on elements, screen readers will default to announcing a generic name, which means your content will be less accessible to users who rely on screen readers.
`[aria-*]` attributes have valid values ARIA attributes cannot be interpreted with invalid values when used by screen readers and other assistive technologies.
`[aria-*]` attributes are valid and not misspelled ARIA attributes cannot be interpreted with invalid names when used by screen readers and other assistive technologies.
ARIA IDs are unique Ensure all ARIA ID values are unique to prevent elements from being overlooked by assistive technologies, like a screen reader.
Contrast
Background and foreground colors have a sufficient contrast ratio Many (if not most) users find low-contrast text difficult or impossible to read.
Tables and lists
`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements. Screen readers and other assistive technologies may produce poor and inaccurate output when definition lists are not properly marked up.
Definition list items are wrapped in `<dl>` elements In order for screen readers and other assistive technologies to properly announce definition list items ('<dt>' and '<dd>'), they must be wrapped in parent a '<dl>' element.
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`). Use proper list structure to aid screen readers and other assistive technologies.
List items (`<li>`) are contained within `<ul>` or `<ol>` parent elements In order for screen readers to announce list items, ensure that list items ('<li>') are contained within parent '<ul>' or '<ol>' tags.
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table. Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that '<td>' cells using the headers attribute only refer to other cells in the same table, to improve screen reader user experience.
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe. Screen readers and other assistive technologies have features to make navigating tables easier. Ensure that table headers refer to some set of cells, to improve screen reader user experience.
Names and labels
Document has a `<title>` element Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
No form fields have multiple labels Having multiple labels for form fields can be confusing to assistive technologies, like a screen reader.
`<frame>` or `<iframe>` elements have a title Screen reader users and other assistive technology users rely on frame titles to describe the contents of frames.
`<input type="image">` elements have `[alt]` text Input buttons with alternative text assist screen readers and other assistive technology users to understand its purpose.
Form elements have associated labels Screen readers and other assistive technologies rely on labels to properly announce form controls.
`<object>` elements have alternate text It is advised that alt text is used on '<object>' elements in order to provide meaning to screen reader and other assistive technology users, as these technologies are unable to translate non-text content.
Internationalization and localization
`<html>` element has a `[lang]` attribute It is advised to provide a lang attribute so that screen readers and other assistive technologies are guaranteed to announce the page's text correctly. When not provided, the user's default language setting will be used which may cause inaccuracies.
`<html>` element has a valid value for its `[lang]` attribute Specify a valid BCP 47 language in order to help screen readers and other assistive technologies announce text properly.
`[lang]` attributes have a valid value Specify a valid BCP 47 language on elements in order to help screen readers and other assistive technologies announce text properly.
Best practices
The document does not use `<meta http-equiv="refresh">` Pages that refresh automatically cause a poor user experience as focus is directed back to the top of the page unexpectedly.
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5. For users with low vision who rely on screen magnification, ensure that zooming is not disabled.
Audio and video
`<video>` elements contain a `<track>` element with `[kind="captions"]` Ncbi.com may provide assistance to deaf or hearing-impaired users with captions on videos.
Names and labels
Buttons do not have an accessible name Buttons become unusable as they are announced simply as "button" when the button does not have an accessible name, when used by screen readers and other assistive technologies.
| Failing Elements |
|---|
Image elements do not have `[alt]` attributes Provide short and descriptive alternative text where possible on informative elements.
| Failing Elements |
|---|
Links do not have a discernible name In order to improve the navigation for screen reader and other assistive technology users, use link text that is unique, focusable and discernible.
| Failing Elements |
|---|
Manual Checks
The page has a logical tab order The visual layout should be logical in its tab order and users cannot focus elements that are offscreen.
Interactive controls are keyboard focusable Ensure that custom interactive controls are keyboard focusable and that a focus indicator is displayed.
Interactive elements indicate their purpose and state Ensure that interactive elements (such as links and buttons) are distinguishable from non-interactive elements and that they indicate their state.
The user's focus is directed to new content added to the page When new content (such as a dialogue) is added to the page, the user's focus should be directed to it.
User focus is not accidentally trapped in a region Avoid focus being accidentally trapped when a user tabs in and out of controls or regions on page.
Custom controls have associated labels Ensure that custom interactive controls have associated labels, which are provided by aria-label and aria-labelledby attributes.
Custom controls have ARIA roles Ensure that all custom interactive controls have appropriate ARIA roles.
Visual order on the page follows DOM order Ensure that the DOM order matches with the page's visual order, in order to improve navigation for screen readers and other assistive technologies.
Offscreen content is hidden from assistive technology Ensure that offscreen content is hidden through the use of "display:none" styling or the aria-hidden attribute.
HTML5 landmark elements are used to improve navigation Elements such as <main> and <nav> are recommended as they are used by screen readers and other assistive technologies to improve keyboard navigation.
Best Practices
Indicates the recommended, best practices currently in place on the page and highlights the best practices that ncbi.com should incorporate. This includes practices such as protecting pages with HTTPS.Audits
Avoids requesting the geolocation permission on page load When requesting a user's location, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids requesting the notification permission on page load When requesting permission to send notifications, provide context or consider tying the request to a user action to avoid confusion and mistrust from users.
Avoids front-end JavaScript libraries with known security vulnerabilities Ensure that the use of third-party scripts is minimal and that only trusted third-party scripts are used as some may contain known security vulnerabilities which may be exploited by attackers.
Ensure CSP is effective against XSS attacks Significantly reduce the risk of cross-site scripting attacks (XSS) by ensuring you have a strong Content Security Policy (CSP).
| Description | Directive | Severity |
|---|---|---|
| No CSP found in enforcement mode | High |
Audits
Allows users to paste into password fields Ensure that password inputs may be pasted into to aid in the user's ability to use password managers and improve security.
Displays images with correct aspect ratio Ensure that image display dimensions match their natural aspect ratio.
Serves images with appropriate resolution For maximum image clarity, ensure images have natural dimensions and are proportional to the display size and pixel ratio.
Fonts with `font-display: optional` are preloaded It is recommended that optional fonts are preloaded.
Audits
Page has the HTML doctype Ensure a doctype is specified to prevent the browser from switching to quirks-mode.
Properly defines charset It is advised to declare a character encoding, optionally via a <meta> tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header.
Audits
Detected JavaScript libraries Below is a list of all front-end JavaScript libraries that were detected on the page.
| Name | Version |
|---|---|
| Bootstrap | 3.4.1 |
| jQuery | 3.5.1 |
| Modernizr | 2.8.3 |
| core-js | core-js-global@2.6.5 |
Avoids deprecated APIs Avoid deprecated APIs which will eventually be removed the browser.
No browser errors logged to the console Below is a list of all errors logged to the console, which indicate unresolved problems on the site.
Page has valid source maps Consider deploying source maps for added benefits such as the ability to debug while in production.
No issues in the `Issues` panel in Chrome Devtools There may be unresolved issues logged to Chrome Devtools.
Audits
Does not use HTTPS — 1 insecure request found Ensure that all pages are protected with HTTPS (including those that do not handle sensitive data) as HTTPS prevents tampering and passive listening on communications between the app and its users. Additionally, HTTPS is a prerequisite for HTTP/2 and many new web platform APIs.
| Insecure URL | Request Resolution |
|---|---|
| http://ncbi.com/ | Allowed |
SEO
Indicates how well the page is optimized for ranking in search engines and highlights Search Engine Optimization (SEO) opportunities for ncbi.com. This includes optimizations such as providing meta data.Mobile Friendly
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Document uses legible font sizes — 100% legible text Font sizes of 12px or less are too small to most mobile users without user gestures and further action. Aim for more than 60% of page text to use font sizes greater than 12px.
| Source | Selector | % of Page Text | Font Size |
|---|---|---|---|
| 100.00% | ≥ 12px |
Content Best Practices
Document has a `<title>` element Search engines, screen reader users and other assistive technology users rely on the title to provide an overview of the page and to help determine if the page is relevant to their search.
Links have descriptive text Make use of descriptive link text to assist search engines in understanding the content.
Document has a valid `hreflang` Search engines can be instructed to list specific versions of a page for a given language or region through the use of hreflang links.
Document has a valid `rel=canonical` Search engines can be suggested which URL should be shown in search results through the use of canonical links.
Document avoids plugins The content of plugins cannot be indexed by search engines and many devices either restrict or do not support them.
Crawling and Indexing
Page has successful HTTP status code Avoid pages with unsuccessful HTTP status codes as they may not be indexed by search engines.
Page isn’t blocked from indexing Pages that cannot be crawled by search engines cannot be indexed or included in their search results. Ensure that search engines have permission to crawl all pages that should be indexed.
robots.txt is valid Malformed robots.txt files prevent crawlers from understanding how a site wants to be crawled or indexed, which can be devastating to SEO.
Mobile Friendly
Tap targets are not sized appropriately — 92% appropriately sized tap targets Interactive elements (such as buttons and links) should be appropriately spaced, sized and easy enough to select or tap with regard to their surrounding elements.
| Tap Target | Size | Overlapping Target |
|---|---|---|
| 30x50 |
Content Best Practices
Document does not have a meta description Meta descriptions may be used by search engines when displaying a link to the page and should concisely summarize the page's content.
Image elements do not have `[alt]` attributes Provide short and descriptive alternative text where possible on informative elements.
| Failing Elements |
|---|
Crawling and Indexing
Links are not crawlable Ensure that the 'href' attribute of anchor elements links to the appropriate destination. This allows for more pages of the site to be discovered by search engines.
| Uncrawlable Link |
|---|
Manual Checks
Structured data is valid Structured data can be validated through the use of the Structured Data Testing Tool and the Structured Data Linter.
PWA
Indicates how valid the aspects of a Progressive Web App (PWA) are for the page and highlights opportunities to enable/improve the PWA of ncbi.com. This includes details about web app manifests.PWA Optimized
Content is sized correctly for the viewport Ensure that the width of the app's content matches the width of the viewport, otherwise the app might not be optimized for mobile screens.
Has a `<meta name="viewport">` tag with `width` or `initial-scale` It is advised to use a '<meta name="viewport">' tag for the optimization of ncbi.com on mobile screens.
Installable
Web app manifest or service worker do not meet the installability requirements — 1 reason User engagement may be increased by leveraging the browsers ability to proactively prompt users to add the app to their homescreen.
| Failure reason |
|---|
| No manifest was fetched |
PWA Optimized
Does not register a service worker that controls page and `start_url` A service worker is used to provide Progressive Web Apps the use of features such as working offline, the ability for the app to be added to the homescreen as well as push notifications.
Is not configured for a custom splash screen Themed splash screens ensure a high-quality user experience at launch for app users.
View Data
Does not set a theme color for the address bar. A theme may be applied to the browser address bar, which ideally can be made to match the site.
View Data
Does not provide a valid `apple-touch-icon` iOS users of Progressive Web Apps will benefit from an apple touch icon, which can be defined with 'apple-touch-icon', which must point to a non-transparent 192px (or 180px) square PNG.
Manifest doesn't have a maskable icon Maskable icons are great to ensure that images fill the entire shape when installing the app on a device.
Manual Checks
Site works cross-browser Ensure that the Progressive Web App works correctly across every major browser.
Page transitions don't feel like they block on the network Users perceive apps with responsive, snappy transitions as higher peforming and ensures a great user experience, even on a slow network.
Each page has a URL Ensure that all pages are deep linkable via URL. They should also be unique for the purpose of shareability on social media.
Hosting
Server Location
| Server IP Address: | 50.233.240.133 |
| Continent: | North America |
| Country: | United States  |
| Region: | California |
| City: | Napa |
| Longitude: | -122.2828 |
| Latitude: | 38.2901 |
| Currencies: | USD USN USS |
| Languages: | English |
Web Hosting Provider
| Name | IP Address |
|---|---|
| Comcast Cable Communications, LLC |
Registration
Domain Registrant
| Private Registration: | No |
| Name: | |
| Organization: |
| Country: | |
| City: | |
| State: | |
| Post Code: | |
| Email: | |
| Phone: |
Note: Registration information is derived from various sources and may be inaccurate.
Domain Registrar
| Name | IP Address |
|---|---|
| Network Solutions, LLC | 162.159.134.53 |
Security
Visitor Safety
| Mature Content: | Not Likely |
| McAfee WebAdvisor Rating: | Safe |
| WOT Rating: | |
| WOT Trustworthiness: | |
| WOT Child Safety: |
Note: Safety information is not guaranteed.
SSL/TLS Certificate
| Issued To: | www.ncbi.com |
| Issued By: | Network Solutions DV Server CA 2 |
| Valid From: | 12th November, 2022 |
| Valid To: | 12th November, 2023 |
| Subject: | CN = www.ncbi.com |
| Hash: | 1a502165 |
| Issuer: | CN = Network Solutions DV Server CA 2 O = Network Solutions L.L.C. S = US |
| Version: | 2 |
| Serial Number: | 143751337459395572392955740168211775099 |
| Serial Number (Hex): | 6C2580231E83D298554CBF53E975BE7B |
| Valid From: | 12th November, 2024 |
| Valid To: | 12th November, 2024 |
| Signature Algorithm (Short Name): | RSA-SHA256 |
| Signature Algorithm (Long Name): | sha256WithRSAEncryption |
| Authority Key Identifier: | keyid:51:CE:DF:54:1D:B7:2C:57:AB:68:61:48:02:1A:D3:B2:85:EC:40:AA |
| Extended Key Usage: | TLS Web Server Authentication, TLS Web Client Authentication |
| CRL Distribution Points: | Full Name: URI:http://crl.netsolssl.com/NetworkSolutionsDVServerCA2.crl |
| Certificate Policies: | Policy: 1.3.6.1.4.1.782.1.2.1.9.1 CPS: http://www.networksolutions.com/legal/SSL-legal-repository-cps.jsp Policy: 2.23.140.1.2.1 |
| Authority Information Access: | CA Issuers - URI:http://crt.netsolssl.com/NetworkSolutionsDVServerCA2.crt OCSP - URI:http://ocsp.netsolssl.com |
| SCT List: | Signed Certificate Timestamp: Version : v1 (0x0) Log ID : AD:F7:BE:FA:7C:FF:10:C8:8B:9D:3D:9C:1E:3E:18:6A: B4:67:29:5D:CF:B1:0C:24:CA:85:86:34:EB:DC:82:8A Timestamp : Nov 12 13:45:20.711 2022 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:1A:6C:83:73:F0:9B:0F:2B:88:F5:78:56: 18:F8:D0:FA:AE:74:C9:95:64:4A:83:F0:07:8B:E7:CB: A6:7D:D6:11:02:21:00:A2:BB:BC:29:3B:6E:BA:FB:9C: B4:DC:E5:62:39:BC:2F:35:36:49:C6:1E:8E:DF:C4:E9: 38:C7:37:A3:AA:12:9C Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 7A:32:8C:54:D8:B7:2D:B6:20:EA:38:E0:52:1E:E9:84: 16:70:32:13:85:4D:3B:D2:2B:C1:3A:57:A3:52:EB:52 Timestamp : Nov 12 13:45:20.689 2022 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:C1:A8:96:7F:07:A4:2D:D8:35:08:D0: B4:2E:F1:43:28:B5:17:BB:C7:3E:98:E0:88:61:8B:3C: 89:6A:6A:9D:59:02:20:30:FC:72:34:4D:75:5C:91:0E: 51:A3:89:F6:70:D6:0B:AC:ED:BB:61:92:5E:B4:0C:9E: B1:A7:29:F7:0C:65:A8 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : E8:3E:D0:DA:3E:F5:06:35:32:E7:57:28:BC:89:6B:C9: 03:D3:CB:D1:11:6B:EC:EB:69:E1:77:7D:6D:06:BD:6E Timestamp : Nov 12 13:45:20.610 2022 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:E4:51:05:EC:0A:27:2B:F1:E7:6C:92: F4:99:66:6E:28:32:94:FF:7D:53:90:7A:AE:6F:F4:7E: FC:B6:31:D2:B3:02:20:52:9C:69:BA:2D:23:6E:FC:73: 2D:18:29:B1:7E:94:83:11:D4:42:B0:6E:13:70:15:98: C3:CF:A0:A3:85:9D:6E |
| Key Usage: | Digital Signature, Key Encipherment |
| Basic Constraints: | CA:FALSE |
| Subject Alternative Name: | DNS:ncbi.com DNS:www.ncbi.com |
Technical
DNS Lookup
HTTP Response Headers
| HTTP-Code: | HTTP/1.1 200 OK |
| Cache-Control: | private |
| Content-Type: | text/html; charset=utf-8 |
| Server: | |
| Date: | 13th January, 2023 |
| Content-Length: | 24381 |
| X-AspNet-Version: | |
| Set-Cookie: | * |
| X-Frame-Options: | DENY |
| Strict-Transport-Security: | max-age=31536000 |
Whois Lookup
| Created: | 21st April, 1998 |
| Changed: | 12th June, 2022 |
| Expires: | 20th April, 2026 |
| Registrar: | Network Solutions, LLC |
| Status: | clientTransferProhibited |
| Nameservers: | ns51.worldnic.com ns52.worldnic.com |
| Owner Name: | PERFECT PRIVACY, LLC |
| Owner Street: | 5335 Gate Parkway care of Network Solutions PO Box 459 |
| Owner Post Code: | 32256 |
| Owner City: | Jacksonville |
| Owner State: | FL |
| Owner Country: | US |
| Owner Phone: | +1.5707088622 |
| Owner Email: | au3yh5767qt@networksolutionsprivateregistration.com |
| Admin Name: | PERFECT PRIVACY, LLC |
| Admin Street: | 5335 Gate Parkway care of Network Solutions PO Box 459 |
| Admin Post Code: | 32256 |
| Admin City: | Jacksonville |
| Admin State: | FL |
| Admin Country: | US |
| Admin Phone: | +1.5707088622 |
| Admin Email: | au3yh5767qt@networksolutionsprivateregistration.com |
| Tech Name: | PERFECT PRIVACY, LLC |
| Tech Street: | 5335 Gate Parkway care of Network Solutions PO Box 459 |
| Tech Post Code: | 32256 |
| Tech City: | Jacksonville |
| Tech State: | FL |
| Tech Country: | US |
| Tech Phone: | +1.5707088622 |
| Tech Email: | qg5zr7qs3c6@networksolutionsprivateregistration.com |
| Full Whois: | Domain Name: NCBI.COM Registry Domain ID: 1136429_DOMAIN_COM-VRSN Registrar WHOIS Server: whois.networksolutions.com Registrar URL: http://networksolutions.com Updated Date: 2022-06-12T06:22:59Z Creation Date: 1998-04-21T04:00:00Z Registrar Registration Expiration Date: 2026-04-20T04:00:00Z Registrar: Network Solutions, LLC Registrar IANA ID: 2 Reseller: Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited Registry Registrant ID: Registrant Name: PERFECT PRIVACY, LLC Registrant Organization: Registrant Street: 5335 Gate Parkway care of Network Solutions PO Box 459 Registrant City: Jacksonville Registrant State/Province: FL Registrant Postal Code: 32256 Registrant Country: US Registrant Phone: +1.5707088622 Registrant Phone Ext: Registrant Fax: Registrant Fax Ext: Registrant Email: au3yh5767qt@networksolutionsprivateregistration.com Registry Admin ID: Admin Name: PERFECT PRIVACY, LLC Admin Organization: Admin Street: 5335 Gate Parkway care of Network Solutions PO Box 459 Admin City: Jacksonville Admin State/Province: FL Admin Postal Code: 32256 Admin Country: US Admin Phone: +1.5707088622 Admin Phone Ext: Admin Fax: Admin Fax Ext: Admin Email: au3yh5767qt@networksolutionsprivateregistration.com Registry Tech ID: Tech Name: PERFECT PRIVACY, LLC Tech Organization: Tech Street: 5335 Gate Parkway care of Network Solutions PO Box 459 Tech City: Jacksonville Tech State/Province: FL Tech Postal Code: 32256 Tech Country: US Tech Phone: +1.5707088622 Tech Phone Ext: Tech Fax: Tech Fax Ext: Tech Email: qg5zr7qs3c6@networksolutionsprivateregistration.com Name Server: NS51.WORLDNIC.COM Name Server: NS52.WORLDNIC.COM DNSSEC: unsigned Registrar Abuse Contact Email: domain.operations@web.com Registrar Abuse Contact Phone: +1.8777228662 URL of the ICANN WHOIS Data Problem Reporting System: http://wdprs.internic.net/ >>> Last update of WHOIS database: 2023-01-13T19:08:26Z <<< For more information on Whois status codes, please visit https://www.icann.org/resources/pages/epp-status-codes-2014-06-16-en This listing is a Network Solutions Private Registration. Mail correspondence to this address must be sent via USPS Express Mail(TM) or USPS Certified Mail(R); all other mail will not be processed. Be sure to include the registrant's domain name in the address. The data in Networksolutions.com's WHOIS database is provided to you by Networksolutions.com for information purposes only, that is, to assist you in obtaining information about or related to a domain name registration record. Networksolutions.com makes this information available "as is," and does not guarantee its accuracy. By submitting a WHOIS query, you agree that you will use this data only for lawful purposes and that, under no circumstances will you use this data to: (1) allow, enable, or otherwise support the transmission of mass unsolicited, commercial advertising or solicitations via direct mail, electronic mail, or by telephone; or (2) enable high volume, automated, electronic processes that apply to Networksolutions.com (or its systems). The compilation, repackaging, dissemination or other use of this data is expressly prohibited without the prior written consent of Networksolutions.com. Networksolutions.com reserves the right to modify these terms at any time. By submitting this query, you agree to abide by these terms. For more information on Whois status codes, please visit https://www.icann.org/resources/pages/epp-status-codes-2014-06-16-en. |
Nameservers
| Name | IP Address |
|---|---|
| ns51.worldnic.com | 162.159.26.165 |
| ns52.worldnic.com | 162.159.27.8 |
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