Netherlands · Amsterdam Completed: Apr 21, 2026 18:58 UTCMobile 375 × 812
Desktop 1440 × 900
Score: 72 / 100
Based on 8 categories, 0 sections
Decent speed, but optimizing further could improve engagement.
Good foundation, but a few gaps could be exploited.
Several issues make your site difficult for assistive technology users.
Missing signals may be hurting your search visibility.
Good server performance with room for optimization.
Mostly compliant — a few items need attention.
Missing metadata means poor previews on social media and search.
Reasonable footprint with room for optimization.
The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.
Weights reflect general web best practices. Individual needs may differ.
Content-Security-Policy header is missing
Security gaps expose your site and users to attacks, eroding trust.
No Content-Security-Policy header found
Security gaps expose your site and users to attacks, eroding trust.
113 third-party resources (100% of weight)
Performance issues directly impact user engagement and conversion rates.
114 HTTP requests — consider bundling or reducing
Performance issues directly impact user engagement and conversion rates.
Cookie 'MACHINE_LAST_SEEN' has no SameSite attribute
Security gaps expose your site and users to attacks, eroding trust.
High impact, low effort — start here.
High impact, requires investment.
Small gains, minimal effort.
Nothing in this quadrant — good news.
Low impact, high effort — do last.
Nothing in this quadrant — good news.
[](https://beavercheck.com/results/4ec11011-9bb0-45ff-8f8e-1b6219c51c9b)<a href="https://beavercheck.com/results/4ec11011-9bb0-45ff-8f8e-1b6219c51c9b"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fthelancet.com" alt="BeaverCheck Score"></a>https://beavercheck.com/badge?url=https%3A%2F%2Fthelancet.comThis badge auto-updates with your latest scan result.
Your site performs reasonably well, but a few targeted fixes could meaningfully improve results. Your LCP of 15.9s exceeds Google's 2.5s 'Good' threshold and the 2 performance issues below directly contribute to it. Addressing the critical issues below would have the most immediate impact on your user trust.
9 barrier(s) likely increasing bounce by ~31%.
Page takes 15.9s to load
+12% bounceUsers abandon at ~3s — you're 13.4s over the 2.5s threshold
Fix: Optimize render-blocking resources, preload the hero image, and compress images
Page feels frozen for 2.0s
+5% bounceClicks on the primary CTA are ignored while JavaScript runs
Fix: Break up long tasks; defer non-critical JavaScript to post-hydration
No HSTS header
+1% bounceReturning visitors are briefly exposed to downgrade attacks on first request
Fix: Set Strict-Transport-Security: max-age=31536000; includeSubDomains
No Content-Security-Policy header
+1% bounceHigher XSS blast radius — one compromised script can exfiltrate the checkout form
Fix: Ship a reporting-only CSP first, then enforce once violations are clean
No Open Graph tags
+2% bounceLinks shared on LinkedIn / Slack / Facebook show bare URLs — referral clicks drop
Fix: Add og:title, og:description, og:image, og:url to the page head
No structured data
+2% bounceNo rich-result eligibility in Google — lower SERP CTR vs competitors with stars and prices
Fix: Add JSON-LD for your page type (Product, Article, FAQPage, LocalBusiness, …)
Thin content
+3% bounceUnder 300 words — visitors bounce looking for substance, search engines rank competitors first
Fix: Add a substantive FAQ, product detail, or case-study section
Content is hard to read
+2% bounceGraduate-level reading difficulty — limits the addressable audience for product or blog pages
Fix: Shorten sentences; replace jargon with plain language; target Flesch ease ≥60
No skip-to-content link
+1% bounceKeyboard and screen-reader users must tab through the entire header on every page
Fix: Add a visible-on-focus <a href="#main">Skip to content</a> as the first focusable element
Preliminary CRO audit — each barrier links to the tab with detailed analysis.
$550 investment → $0.63/month returns + USD 150,000 risk avoided
$550
6h · 5 findings
$0.63 /mo
~$7.51 / year
USD 150,000
if kept compliant
$150 — in quick wins — start here for the fastest payback
Figures combine localized regulatory fine ceilings, search/conversion value priced against local CPC, and bandwidth waste estimates. Results depend on implementation quality and audience composition. Not legal or financial advice.
5.5 developer hours at $100/hr
Based on United States rates ($100/hr)
Start here for the best return on investment
$12,501 / month at risk
~$150,008 / year if left unfixed
$150,000
$0.63 /mo
7819.1 MB/mo × 0.080 USD/GB
Compliance figures represent the statutory maximum fine for the most severe triggered category, capped per regulation — not the sum of per-finding penalties. Based on published regulatory fine ranges. This is not legal advice.
Unique monthly visitors from your analytics
Purchases, signups, or key actions
Optional — for revenue estimation
more engaged visitors from reduced bounce
Fix 2 critical issues to capture this value
Based on Google/Deloitte research ("Milliseconds Make Millions") showing a ~7% bounce rate increase per additional second of LCP above the 2.5s "Good" threshold.
Your site's LCP: → estimated after fixes.
These are estimates based on industry research — actual results vary
Your data stays in your browser — nothing is sent to our servers
Thanks for your feedback!
We'll use a cached audit if available, or offer to scan.
Industry-standard audits powered by Google Lighthouse.
Key metrics that affect user experience.
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
4.73 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
15.92 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
2.04 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.086
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
9.37 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
20.65 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Performance issues directly impact user engagement and conversion rates.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.
Most users today run browsers that natively support ES6+, async/await, optional chaining, and the rest of modern JavaScript. Transpiling to ES5 'just in case' adds 20-40% to your bundle for no benefit. Configure your build to target a modern browserslist, or ship a differential bundle pair (modern + legacy) with the module/nomodule pattern.
Source: Google web.dev / Lighthouse
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
Performance issues directly impact user engagement and conversion rates.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
Children stacking their hands on top of one another on a grassy field. Copyrigh… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 61.6 KiB | 53.0 KiB |
Fishermen unload mangrove seedlings that they will plant along a coastal area a… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 56.4 KiB | 47.8 KiB |
The Lancet Summit: shaping the future of diabetes prevention. Image credit: Ixe… body.jar > div#google_image_div > a#aw0 > img.img_ad | tpc.googlesyndication.com/simgad/11323284346351336585 | 44.9 KiB | 42.5 KiB |
A medical professional is holding a smear test kit for HPV. Copyright: Peter Da… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 43.0 KiB | 34.4 KiB |
A logo for The Lancet Pulse podcast which features a blue background and white … div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 19.3 KiB | 10.7 KiB |
Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.
Performance issues directly impact user engagement and conversion rates.
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Performance issues directly impact user engagement and conversion rates.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Duration |
|---|---|---|
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 68.3 KiB | 1.4 s |
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 4.1 KiB | 182 ms |
| www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~product.css | 13.4 KiB | 634 ms |
| cdn.cookielaw.org/scripttemplates/otSDKStub.js | 9.1 KiB | 1.1 s |
| fonts.googleapis.com/css?family=Open+Sans | 2.0 KiB | 765 ms |
| www.thelancet.com/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js | 850 B | 483 ms |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| thelancet.com/ | 935 ms |
| /as/authorization.oauth2?platSite=LT%2Fthelancet&response... | 866 ms |
| /callback?red_uri=%2F&code=V3QOlhBAVO6PUAsqIxwlhWnP-pPwhl... | 499 ms |
| www.thelancet.com/ | 0.0 ms |
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.
Performance issues directly impact user engagement and conversion rates.
The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.
Performance issues directly impact user engagement and conversion rates.
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.thelancet.com/pb-assets/Lancet/homepage/carousel/js/flickity.pkgd.js | 25.8 KiB | 9.9 KiB |
| inline: function gpt_CheckEnvironment() { … | 11.5 KiB | 6.4 KiB |
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| /products/marlin/lancet/releasedAssets/css/build-02c4f504... | 104.6 KiB | 100.6 KiB |
| 25.3 KiB | 22.0 KiB | |
| www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~product.css | 13.1 KiB | 12.9 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Multi-megabyte JavaScript bundles delay every interactive feature on the page.
This is the Lighthouse audit fired when too much JS is shipped relative to what executes. The fix isn't a config flag — it requires bundle analysis (webpack-bundle-analyzer, rollup-plugin-visualizer), splitting routes into chunks, lazy-loading off-screen components, and removing unused dependencies. Fundamentally different from minification: minifying reduces byte count, this reduces what's downloaded at all.
Source: Google web.dev / Lighthouse
| URL | Transfer Size | Est Savings |
|---|---|---|
| /products/marlin/lancet/releasedAssets/js/main.bundle-582... | 217.7 KiB | 149.2 KiB |
| /pagead/managed/js/gpt/m202604090102/pubads_impl.js?cb=31... | 187.6 KiB | 101.0 KiB |
| cdn.cookielaw.org/scripttemplates/202505.2.0/otBannerSdk.js | 119.0 KiB | 62.1 KiB |
| www.googletagmanager.com/gtag/js?id=AW-800477382 | 140.7 KiB | 58.1 KiB |
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 68.0 KiB | 51.5 KiB |
| /pagead/managed/js/activeview/current/ufs_web_display.js | 73.1 KiB | 31.1 KiB |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
Performance issues directly impact user engagement and conversion rates.
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work
Performance issues directly impact user engagement and conversion rates.
| Category | Time Spent |
|---|---|
| Script Evaluation | 5.6 s |
| Style & Layout | 2.3 s |
| Other | 1.5 s |
| Script Parsing & Compilation | 734 ms |
| Rendering | 494 ms |
| Parse HTML & CSS | 401 ms |
| Garbage Collection | 171 ms |
Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache
Performance issues directly impact user engagement and conversion rates.
| Failure reason | Failure type |
|---|---|
| The page has an unload handler in the main frame. | Actionable |
Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.thelancet.com/pb-assets/Lancet/homepage/carousel/css/flickity-docs.css | 10.3 KiB | 3.5 KiB |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Performance issues directly impact user engagement and conversion rates.
| URL | |
|---|---|
A logo for The Lancet Pulse podcast which features a blue background and white … div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
Fishermen unload mangrove seedlings that they will plant along a coastal area a… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
A medical professional is holding a smear test kit for HPV. Copyright: Peter Da… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
Children stacking their hands on top of one another on a grassy field. Copyrigh… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
The Lancet Home div.journal-logos > span > a > img | www.thelancet.com/pb-assets/ux3/logos/lancet/LANCET-1665147351037.svg |
The Lancet logo div.footer__top > div.footer__logo > a > img | www.thelancet.com/pb-assets/ux3/logos/lancet/LANCET-1665147351037.svg |
Advertisement div.horizontalAdContainer > div.horizontalAdLabelContainer > div.horizontalAdLabel > img | www.thelancet.com/templates/jsp/_style2/_marlin/images/bg_adHoriz.gif |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
back main#pageBody > div.w-slide > div.w-slide_head > a.w-slide__back |
These are opportunities to improve the legibility of your content.
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Listen to the latest episode of The Lancet Pulse podcast which discusses the wo… li.publication-list__article > div.publication-list__article__content__wrapper > div.publication-list__article__content > h4#S1470204523006459-title |
Embedding social prescribing in primary care in England and Scotland: a qualita… section > div.search__item__body > span.hlFld-Title > h4.meta__title |
These are opportunities to improve keyboard navigation in your application.
Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
head > meta head > meta |
Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Accessibility div.align-center > div > p.align-center > a |
These items highlight common accessibility best practices.
Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Cookie settings div.align-center > div > p.align-center > button#cookieBtn |
Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.
Performance issues directly impact user engagement and conversion rates.
| URL | Displayed size | Actual size | Expected size | |
|---|---|---|---|---|
A logo for The Lancet Pulse podcast which features a blue background and white … div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 380 x 241 | 288 x 183 | 570 x 362 |
Advertisement div.horizontalAdContainer > div.horizontalAdLabelContainer > div.horizontalAdLabel > img | www.thelancet.com/templates/jsp/_style2/_marlin/images/bg_adHoriz.gif | 9 x 72 | 10 x 80 | 14 x 108 |
Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.
Performance issues directly impact user engagement and conversion rates.
| Deprecation / Warning | Source |
|---|---|
| SharedStorage | /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... line 1, col 2440 |
| StorageType.persistent is deprecated. Please use standardized navigator.storage instead. | |
| Fledge | |
| Unload event listeners are deprecated and will be removed. | www.thelancet.com/ line 11, col 26065 |
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit
Performance issues directly impact user engagement and conversion rates.
| Source | Description |
|---|---|
Failed to load resource: the server responded with a status of 403 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
/products/marlin/lancet/releasedAssets/js/main.bundle-582... line 8, col 43193 | NetworkError: A network error occurred. |
SyntaxError: Failed to execute 'appendChild' on 'Node': Unexpected token ':'
at HTMLHeadElement.nrWrapper [as appendChild] (https://www.thelancet.com/:12:26066)
at m (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:880)
at ce.globalEval (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:3031)
at text script (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:80994)
at https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:77349
at l (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:77466)
at XMLHttpRequest.<anonymous> (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:80265)
at XMLHttpRequest.nrWrapper (https://www.thelancet.com/:12:26066) | |
www.thelancet.com/ line 3294, col 61 | TypeError: Cannot read properties of null (reading 'getElementsByTagName')
at https://www.thelancet.com/:3295:62 |
Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.
Performance issues directly impact user engagement and conversion rates.
| Issue type |
|---|
| Content security policy |
Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.
Performance issues directly impact user engagement and conversion rates.
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable
Performance issues directly impact user engagement and conversion rates.
| Uncrawlable Link |
|---|
Close search options form > div.quick-search__box > div.quick-search__box-inner > a.quick-search__box-close |
To appear in search results, crawlers need access to your app.
Industry-standard audits powered by Google Lighthouse. — Desktop
Key metrics that affect user experience. — Desktop
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.33 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.03 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
205 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.117
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
3.34 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
4.45 s
Audit breakdown by category with detailed findings.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.
Performance issues directly impact user engagement and conversion rates.
Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling
Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.
Most users today run browsers that natively support ES6+, async/await, optional chaining, and the rest of modern JavaScript. Transpiling to ES5 'just in case' adds 20-40% to your bundle for no benefit. Configure your build to target a modern browserslist, or ship a differential bundle pair (modern + legacy) with the module/nomodule pattern.
Source: Google web.dev / Lighthouse
3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.
Performance issues directly impact user engagement and conversion rates.
A long cache lifetime can speed up repeat visits to your page. Learn more about caching.
Performance issues directly impact user engagement and conversion rates.
Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.
Performance issues directly impact user engagement and conversion rates.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.
Performance issues directly impact user engagement and conversion rates.
Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.
Performance issues directly impact user engagement and conversion rates.
Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size
Performance issues directly impact user engagement and conversion rates.
| URL | Resource Size | Est Savings | |
|---|---|---|---|
The Lancet Summit: shaping the future of diabetes prevention. Image credit: Ixe… body.jar > div#google_image_div > a#aw0 > img.img_ad | tpc.googlesyndication.com/simgad/3034105075962818447 | 109.7 KiB | 99.0 KiB |
A community meeting at a Health and Wellness Centre in Nazardih village, Nawada… div.do-card > div.do-item-media > a > img | /do/10.1016/4f9d9162-93c9-4d6f-ac08-283f4e73cd6d/single_c... | 99.3 KiB | 92.0 KiB |
Cancer cells under an automated fluorescence microscope div.do-card > div.do-item-media > a > img | /do/10.1016/a7d423f9-578d-40e1-89a3-8addecd9517e/single_c... | 90.3 KiB | 83.0 KiB |
Children stacking their hands on top of one another on a grassy field. Copyrigh… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 61.6 KiB | 53.0 KiB |
Fishermen unload mangrove seedlings that they will plant along a coastal area a… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 56.4 KiB | 47.8 KiB |
Female doctor holding hands of stressed patient while consoling at clinic div.do-card > div.do-item-media > a > img | /do/10.1016/2e3f8d55-c132-448b-8470-b6492f45d646/single_c... | 55.0 KiB | 47.7 KiB |
A boy looking at a single electric lightbulb, powered by solar technology, as i… div.do-card > div.do-item-media > a > img | /do/10.1016/04f8c4ae-ce4a-414f-9e8c-da80cc73d001/single_c... | 55.7 KiB | 47.5 KiB |
A medical professional is holding a smear test kit for HPV. Copyright: Peter Da… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 43.0 KiB | 34.4 KiB |
A logo for The Lancet Pulse podcast which features a blue background and white … div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... | 19.3 KiB | 10.7 KiB |
Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.
Performance issues directly impact user engagement and conversion rates.
Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Duration |
|---|---|---|
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 68.3 KiB | 314 ms |
| cdn.cookielaw.org/scripttemplates/otSDKStub.js | 9.1 KiB | 262 ms |
| fonts.googleapis.com/css?family=Open+Sans | 2.0 KiB | 216 ms |
| www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~product.css | 13.4 KiB | 68 ms |
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 4.1 KiB | 68 ms |
| www.thelancet.com/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js | 800 B | 150 ms |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.
Performance issues directly impact user engagement and conversion rates.
| URL | Time Spent |
|---|---|
| thelancet.com/ | 383 ms |
| /as/authorization.oauth2?platSite=LT%2Fthelancet&response... | 301 ms |
| /callback?red_uri=%2F&code=Sst7dXe1Qp01Q5QFUmVnCG3PS_5YrL... | 168 ms |
| www.thelancet.com/ | 0.0 ms |
These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS
Performance issues directly impact user engagement and conversion rates.
| Element | Layout shift score |
|---|---|
The Lancet
AI in primary care: innovations and challenges
Latest news and comme… body.pb-ui > div#pb-page-content > div > main#pageBody | 0.081 |
The Lancet
AI in primary care: innovations and challenges
Latest news and comme… body.pb-ui > div#pb-page-content > div > main#pageBody | 0.059 |
NEW PODCAST
Listen to the latest episode of The Lancet Pulse podcast which disc… div.container > div.row > div.col-xs-12 > div.highlights-art-layout-outer | 0.058 |
Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.
Performance issues directly impact user engagement and conversion rates.
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| /products/marlin/lancet/releasedAssets/css/build-02c4f504... | 103.6 KiB | 100.1 KiB |
| 25.3 KiB | 21.1 KiB | |
| www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~product.css | 13.1 KiB | 12.9 KiB |
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Multi-megabyte JavaScript bundles delay every interactive feature on the page.
This is the Lighthouse audit fired when too much JS is shipped relative to what executes. The fix isn't a config flag — it requires bundle analysis (webpack-bundle-analyzer, rollup-plugin-visualizer), splitting routes into chunks, lazy-loading off-screen components, and removing unused dependencies. Fundamentally different from minification: minifying reduces byte count, this reduces what's downloaded at all.
Source: Google web.dev / Lighthouse
| URL | Transfer Size | Est Savings |
|---|---|---|
| /products/marlin/lancet/releasedAssets/js/main.bundle-582... | 216.4 KiB | 148.4 KiB |
| /pagead/managed/js/gpt/m202604160201/pubads_impl.js | 187.7 KiB | 100.4 KiB |
| cdn.cookielaw.org/scripttemplates/202505.2.0/otBannerSdk.js | 119.0 KiB | 62.1 KiB |
| www.googletagmanager.com/gtag/js?id=AW-800477382 | 140.7 KiB | 57.5 KiB |
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 68.0 KiB | 51.5 KiB |
| /pagead/managed/js/activeview/current/ufs_web_display.js | 73.1 KiB | 31.0 KiB |
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.
Performance issues directly impact user engagement and conversion rates.
| URL | Total CPU Time | Script Evaluation | Script Parse |
|---|---|---|---|
| www.thelancet.com/ | 1.1 s | 390 ms | 12 ms |
| Unattributable | 312 ms | 54 ms | 0.0 ms |
| /pagead/managed/js/gpt/m202604160201/pubads_impl.js | 307 ms | 238 ms | 33 ms |
| /products/marlin/lancet/releasedAssets/js/main.bundle-582... | 233 ms | 143 ms | 37 ms |
| /pagead/managed/js/activeview/current/ufs_web_display.js | 132 ms | 105 ms | 12 ms |
| www.thelancet.com/cdn-cgi/challenge-platform/scripts/jsd/main.js | 117 ms | 112 ms | 1.3 ms |
| cdn.cookielaw.org/scripttemplates/202505.2.0/otBannerSdk.js | 110 ms | 70 ms | 22 ms |
| /products/marlin/lancet/releasedAssets/js/lazy-imports-35... | 58 ms | 38 ms | 1.8 ms |
| /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... | 50 ms | 30 ms | 14 ms |
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work
Performance issues directly impact user engagement and conversion rates.
| Category | Time Spent |
|---|---|
| Script Evaluation | 1.4 s |
| Style & Layout | 583 ms |
| Other | 377 ms |
| Script Parsing & Compilation | 189 ms |
| Rendering | 131 ms |
| Parse HTML & CSS | 106 ms |
| Garbage Collection | 22 ms |
Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache
Performance issues directly impact user engagement and conversion rates.
| Failure reason | Failure type |
|---|---|
| The page has an unload handler in the main frame. | Actionable |
Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.thelancet.com/pb-assets/Lancet/homepage/carousel/css/flickity-docs.css | 10.3 KiB | 3.5 KiB |
Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.thelancet.com/pb-assets/Lancet/homepage/carousel/js/flickity.pkgd.js | 25.8 KiB | 9.9 KiB |
| inline: function gpt_CheckEnvironment() { … | 11.6 KiB | 6.5 KiB |
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions
Performance issues directly impact user engagement and conversion rates.
| URL | |
|---|---|
Cancer cells under an automated fluorescence microscope div.do-card > div.do-item-media > a > img | /do/10.1016/a7d423f9-578d-40e1-89a3-8addecd9517e/single_c... |
A community meeting at a Health and Wellness Centre in Nazardih village, Nawada… div.do-card > div.do-item-media > a > img | /do/10.1016/4f9d9162-93c9-4d6f-ac08-283f4e73cd6d/single_c... |
Female doctor holding hands of stressed patient while consoling at clinic div.do-card > div.do-item-media > a > img | /do/10.1016/2e3f8d55-c132-448b-8470-b6492f45d646/single_c... |
A logo for The Lancet Pulse podcast which features a blue background and white … div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
Fishermen unload mangrove seedlings that they will plant along a coastal area a… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
A medical professional is holding a smear test kit for HPV. Copyright: Peter Da… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
Children stacking their hands on top of one another on a grassy field. Copyrigh… div.highlights-img-inner > span > a > img | /pb-assets/Lancet/homepage/latest_news/latest-news-260411... |
A boy looking at a single electric lightbulb, powered by solar technology, as i… div.do-card > div.do-item-media > a > img | /do/10.1016/04f8c4ae-ce4a-414f-9e8c-da80cc73d001/single_c... |
The Lancet Home div.journal-logos > span > a > img | www.thelancet.com/pb-assets/ux3/logos/lancet/LANCET-1665147351037.svg |
The Lancet logo div.footer__top > div.footer__logo > a > img | www.thelancet.com/pb-assets/ux3/logos/lancet/LANCET-1665147351037.svg |
Advertisement div.horizontalAdContainer > div.horizontalAdLabelContainer > div.horizontalAdLabel > img | www.thelancet.com/templates/jsp/_style2/_marlin/images/bg_adHoriz.gif |
More information about the performance of your application. These numbers don't directly affect the Performance score.
These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.
Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Journals
Publish
Clinical
Global health
Multimedia
Events
About div.widget-body > nav#mega-menu-nav > div.mega-menu-nav__wrapper > ul#mega-menu-box |
These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.
Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
back main#pageBody > div.w-slide > div.w-slide_head > a.w-slide__back |
These are opportunities to improve the legibility of your content.
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Listen to the latest episode of The Lancet Pulse podcast which discusses the wo… li.publication-list__article > div.publication-list__article__content__wrapper > div.publication-list__article__content > h4#S1470204523006459-title |
Embedding social prescribing in primary care in England and Scotland: a qualita… section > div.search__item__body > span.hlFld-Title > h4.meta__title |
These are opportunities to improve keyboard navigation in your application.
Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
head > meta head > meta |
These items highlight common accessibility best practices.
Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.
Performance issues directly impact user engagement and conversion rates.
| Failing Elements |
|---|
Cookie settings div.align-center > div > p.align-center > button#cookieBtn |
Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.
Performance issues directly impact user engagement and conversion rates.
| Deprecation / Warning | Source |
|---|---|
| SharedStorage | /wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-le... line 1, col 2440 |
| StorageType.persistent is deprecated. Please use standardized navigator.storage instead. | |
| Fledge | |
| Unload event listeners are deprecated and will be removed. | www.thelancet.com/ line 11, col 26065 |
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit
Performance issues directly impact user engagement and conversion rates.
| Source | Description |
|---|---|
Failed to load resource: the server responded with a status of 403 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
Failed to load resource: the server responded with a status of 404 () | |
/products/marlin/lancet/releasedAssets/js/main.bundle-582... line 8, col 43193 | NetworkError: A network error occurred. |
SyntaxError: Failed to execute 'appendChild' on 'Node': Unexpected token ':'
at HTMLHeadElement.nrWrapper [as appendChild] (https://www.thelancet.com/:12:26066)
at m (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:880)
at ce.globalEval (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:3031)
at text script (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:80994)
at https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:77349
at l (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:77466)
at XMLHttpRequest.<anonymous> (https://www.thelancet.com/wro/f03726d8be65c99af4dc13935c7996e819a5ff0d~selected-legacy.js:2:80265)
at XMLHttpRequest.nrWrapper (https://www.thelancet.com/:12:26066) | |
www.thelancet.com/ line 3294, col 61 | TypeError: Cannot read properties of null (reading 'getElementsByTagName')
at https://www.thelancet.com/:3295:62 |
Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.
Performance issues directly impact user engagement and conversion rates.
| Issue type |
|---|
| Content security policy |
Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.
Performance issues directly impact user engagement and conversion rates.
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable
Performance issues directly impact user engagement and conversion rates.
| Uncrawlable Link |
|---|
Close search options form > div.quick-search__box > div.quick-search__box-inner > a.quick-search__box-close |
To appear in search results, crawlers need access to your app.
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