Lighthouse Mobile
· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.Detailed Report
Audit breakdown by category with detailed findings.
Performance
Insights
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
Performance issues directly impact user engagement and conversion rates.
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.
A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.
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 | |
|---|---|---|---|
A technologist, wearing purple glove and safety glasses performing structural a… div#0c20bd02-90a8-4576-9b83-7c1ee9742e03 > div.MuiGrid2-root > div.css-1171iwm > img.css-11t9eax | /optim/dotcom/content-app/events/quaterly-results/2026/20... | 40.1 KiB | 35.4 KiB |
Two women in black wetsuits standing on a beach with a surfboard, ready for sur… div.MuiBox-root > div.css-1r6ctyz > div.css-gnhiq7 > img.css-1c67837 | /optim/dot-shared/campaigns/chasing-miracles-brand-campai... | 15.5 KiB | 12.9 KiB |
div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17zqb5e > img.css-131dgat div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17zqb5e > img.css-131dgat | /optim/dotcom/pages/images/our-science/herobanner-our-sci... | 16.4 KiB | 10.3 KiB |
div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17zqb5e > img.css-131dgat div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17zqb5e > img.css-131dgat | /optim/dotcom/pages/images/our-company/our-strategy/herob... | 15.0 KiB | 9.4 KiB |
A man wearing glasses and a blue jacket operates a video camera and looks focus… div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17zqb5e > img.css-131dgat | /optim/dot-shared/campaigns/chasing-miracles-brand-campai... | 10.3 KiB | 6.5 KiB |
Two people sitting at a table indoors with a view of the Eiffel Tower through l… div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-17swrtd > img.css-18bwhs3 | /optim/dot-shared/images/people/Banner-image_expedited-ap... | 18.7 KiB | 5.9 KiB |
Mark, who lives with severe hemophilia A, with his family. div.elements-ds-1bm7awf > div.dotcom-image-wrapper > div.css-1g0l456 > img.css-18bwhs3 | /optim/dotcom/content-app/articles/your-health/its-time-t... | 13.7 KiB | 4.3 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 |
|---|---|---|
| /maps/api/js?key=AIzaSyBcnZwd_VnGoXhzYuIwB1OmktJT8JqHtdg&... | 178.8 KiB | 2.6 s |
| www.sanofi.com/static/root-BEz0SzhB.css | 3.8 KiB | |
| /css2?family=Material+Symbols+Rounded:opsz,wght,FILL,GRAD... | 746 B | 759 ms |
These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.
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.
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 |
|---|---|
| sanofi.com/ | 801 ms |
| www.sanofi.com/ | 794 ms |
| www.sanofi.com/en | 0.0 ms |
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.
Diagnostics
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
Performance issues directly impact user engagement and conversion rates.
| URL | Transfer Size | Est Savings |
|---|---|---|
| www.sanofi.com/static/AppLayout-6piovGy6.js | 337.8 KiB | 161.5 KiB |
| /maps/api/js?key=AIzaSyBcnZwd_VnGoXhzYuIwB1OmktJT8JqHtdg&... | 178.5 KiB | 99.5 KiB |
| www.sanofi.com/static/entry.client-Cy_d_QM4.js | 135.0 KiB | 83.4 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-N67QVH3 | 162.3 KiB | 80.8 KiB |
| cdn.cookielaw.org/scripttemplates/202510.2.0/otBannerSdk.js | 124.0 KiB | 65.5 KiB |
| www.googletagmanager.com/gtm.js?id=GTM-W5BRX7C2>m=4e64k1 | 130.3 KiB | 65.3 KiB |
| maps.googleapis.com/maps-api-v3/api/js/64/9c/util.js | 100.1 KiB | 37.8 KiB |
| maps.googleapis.com/maps-api-v3/api/js/64/9c/common.js | 41.0 KiB | 30.1 KiB |
| www.sanofi.com/static/emotion-element-f0de968e.browser.esm-EbcDOLxY.js | 51.1 KiB | 29.0 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.sanofi.com/static/entry.client-Cy_d_QM4.js | 2.9 s | 2.4 s | 4.7 ms |
| www.sanofi.com/en | 2.0 s | 30 ms | 22 ms |
| www.sanofi.com/static/AppLayout-6piovGy6.js | 1.7 s | 593 ms | 8.1 ms |
| Unattributable | 1.5 s | 383 ms | 0.0 ms |
| www.googletagmanager.com/gtm.js?id=GTM-N67QVH3 | 689 ms | 368 ms | 197 ms |
| cdn.cookielaw.org/scripttemplates/202510.2.0/otBannerSdk.js | 392 ms | 253 ms | 74 ms |
| /maps/api/js?key=AIzaSyBcnZwd_VnGoXhzYuIwB1OmktJT8JqHtdg&... | 364 ms | 216 ms | 138 ms |
| www.googletagmanager.com/gtm.js?id=GTM-W5BRX7C2>m=4e64k1 | 306 ms | 218 ms | 83 ms |
| cdn.cookielaw.org/scripttemplates/otSDKStub.js | 84 ms | 58 ms | 6.6 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 | 4.6 s |
| Other | 2.3 s |
| Style & Layout | 1.3 s |
| Rendering | 947 ms |
| Script Parsing & Compilation | 542 ms |
| Parse HTML & CSS | 222 ms |
| Garbage Collection | 152 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 |
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.
Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.
Performance issues directly impact user engagement and conversion rates.
More information about the performance of your application. These numbers don't directly affect the Performance score.
Accessibility
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.
Navigation
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 |
|---|
We’re proud to spotlight those who inspire us to keep going further in the work… div#b901fa86-2a41-448a-9246-49bd2a8d10e3 > div.MuiGrid2-root > div > h4.MuiTypography-root |
These are opportunities to improve keyboard navigation in your application.
Best Practices
General
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 |
|---|---|
| Unload event listeners are deprecated and will be removed. | www.sanofi.com/static/entry.client-Cy_d_QM4.js line 6, col 43649 |
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 |
|---|---|
Access to font at 'https://cdn.prod.accelerator.sanofi/fonts/sanofi-serif/woff2/Sanofi_Serif-Bold_Italic.woff2' from origin 'https://www.sanofi.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. | |
Access to font at 'https://cdn.prod.accelerator.sanofi/fonts/sanofi-serif/woff2/Sanofi_Serif-Bold_Italic.woff2' from origin 'https://www.sanofi.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. | |
www.sanofi.com/static/entry.client-Cy_d_QM4.js line 52, col 31423 | Error: Minified React error #418; visit https://react.dev/errors/418?args[]=HTML&args[]= for the full message or use the non-minified dev environment for full errors and additional helpful warnings.
at _i (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:31424)
at _p (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:82806)
at Qp (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:117095)
at t6 (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:117067)
at e6 (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:116922)
at Gp (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:112407)
at ch (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:53:124569)
at MessagePort.Ce (https://www.sanofi.com/static/entry.client-Cy_d_QM4.js:46:54107) |
Failed to load resource: net::ERR_FAILED | |
Failed to load resource: net::ERR_FAILED |
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.
SEO
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.
Content Best Practices
Descriptive link text helps search engines understand your content. Learn how to make links more accessible.
Performance issues directly impact user engagement and conversion rates.
| Link destination | Link Text |
|---|---|
| www.sanofi.com/en/chasing-miracles | Learn more |
| /en/chasing-miracles/people-stories/celine-story-multiple... | Read more |
| /en/chasing-miracles/people-stories/xavier-story-autoimmu... | Read more |
| /en/chasing-miracles/people-stories/wei-story-artificial-... | Read more |
| www.sanofi.com/en/our-company/our-strategy | Read more |
| www.sanofi.com/en/our-science | Read more |
| www.sanofi.com/en/patients | Read more |
| www.sanofi.com/en/our-company/sustainability | Read more |
| cookiepedia.co.uk/giving-consent-to-cookies | More information |
Format your HTML in a way that enables crawlers to better understand your app’s content.