Lighthouse Desktop

· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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.

Why this matters

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

Why this matters

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.

Why this matters

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
www.sncf-connect.com/widget/web-widgets-v1.0.0.js	300.0 s	303.9 KiB
www.datadoghq-browser-agent.com/eu1/v6/datadog-rum.js	14400.0 s	58.3 KiB
dd.sncf-connect.com/tags.js	3600.0 s	42.7 KiB
/0586d340-3ead-4a60-9722-29faa78e91a6/loader.js?target=ww...	7200.0 s	40.4 KiB
tags.tiqcdn.com/utag/e-voyageurs-sncf/s2s/prod/utag.js	300.0 s	18.2 KiB

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]

items: [map[node:map[type:text value:Total] score:0.101698] map[node:map[boundingRect:map[bottom:779 height:618 left:0 right:1350 top:161 width:1350] lhId:page-6-DIV nodeLabel:Continuer sans accepter → Votre vie privée est notre priorité Avec votre accor… path:1,HTML,1,BODY,1,DIV,0,DIV,0,DIV,1,DIV selector:div#didomi-host > div.notranslate > div#didomi-popup > div.didomi-exterior-border snippet:<div class="didomi-exterior-border didomi-popup__exterior-border"> type:node] score:0.09648 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:358 height:165 left:405 right:945 top:193 width:541] lhId:page-9-IMG nodeLabel:SNCF Connect coeur et mains path:1,HTML,1,BODY,1,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,DIV,1,DIV,0,IMG selector:div.didomi-popup-container > div.didomi-popup-view > div.didomi-popup-notice-logo-container > img.didomi-popup-notice-logo snippet:<img class="didomi-popup-notice-logo" alt="SNCF Connect coeur et mains" src="https://www.sncf-connect.com/didomi-popin-handshake.svg" role="heading" aria-level="1"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:204 height:76 left:169 right:1181 top:128 width:1011] lhId:page-1-DIV nodeLabel:Recherchez une destination, un trajet, un numéro de train... path:1,HTML,1,BODY,9,DIV,1,DIV,1,DIV,1,MAIN,0,SECTION,1,ARTICLE,0,DIV,2,DIV,0,DIV selector:article.node > div.vsc__node-content > div#universal-search > div.vsc-universal-search__heading snippet:<div class="vsc-universal-search__heading vsc-universal-search__heading--desktop"> type:node] score:0.005218]]

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Resource Size	Est Savings
div#vsc-slide_1 > div.vsc-hero-slide__wrapper > div.vsc-hero-slide__image-wrapper > img.vsc-hero-slide__image `div#vsc-slide_1 > div.vsc-hero-slide__wrapper > div.vsc-hero-slide__image-wrapper > img.vsc-hero-slide__image`	www.sncf-connect.com/assets/media/2026-03/img_homepage_1245x700_7.jpg	214.9 KiB	154.5 KiB

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-0-IMG

nodeLabel: div#vsc-slide_1 > div.vsc-hero-slide__wrapper > div.vsc-hero-slide__image-wrapper > img.vsc-hero-slide__image

path: 1,HTML,1,BODY,9,DIV,1,DIV,1,DIV,1,MAIN,0,SECTION,1,ARTICLE,0,DIV,6,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,IMG

selector: div#vsc-slide_1 > div.vsc-hero-slide__wrapper > div.vsc-hero-slide__image-wrapper > img.vsc-hero-slide__image

snippet: <img class="vsc-hero-slide__image vsc-hero-slide__image--on" alt="" data-image="https://www.sncf-connect.com/assets/media/2026-03/img_homepage_1245x700_7.…" src="https://www.sncf-connect.com/assets/media/2026-03/img_homepage_1245x700_7.…">

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

value: No additional origins are good candidates for preconnecting

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
/themes/custom/mercure_sb/dist/js/00-base/global/widget-l...	459 B
www.sncf-connect.com/widget/web-widgets-v1.0.0.js	303.9 KiB
/assets/js/js_u1AZ9v72ME4UB-mH-zEleVwcdODBjfaT3bLBMsuHs60...	2.0 KiB
/assets/js/js_OtrwUn2Wj7lZGEluUT2DDpO2CTITGPeHNbv6FTPUAZA...	7.8 KiB
www.sncf-connect.com/themes/custom/mercure_sb/dist/css/main.css?tcih7w	17.9 KiB
/assets/asset_injector/js/op_festivals_ete-5d4e072bc1616b...	511 B
/assets/js/js_hh3IOHrfXEGTLVkkuLgwMLwoBTx_6XjxOSDEjynXq9o...	9.7 KiB
/assets/js/js_GPvrhW60mafr0YU742BMfwPu569xjJXhcNVbwO6YHTM...	6.3 KiB
/themes/custom/mercure_sb/dist/js/00-base/global/widget-c...	273 B
/themes/custom/mercure_sb/dist/vendors/js/ad-common.js?tc...	2.8 KiB
/assets/css/css_YHiGtGZQTqaC4RJQTspHRwZn0RaQv3Akw2GQpqqZ2...	11.4 KiB
/assets/css/css_dpUxZ_bsAD54VdB6-a-JQ8AJAXH_pEFj8WoGrsoEq...	46.0 KiB	80 ms
/assets/css/css_cwy7vZiZyn4AG9dyEGu-4SnJ1NW2F63W41JpRLHnD...	1.2 KiB
/assets/js/js_Zp0AWycn6jvnEUkHjUeCKEtXrHRBw-ZAhDXBzkjzqB0...	661 B

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 240 ms 362.5 KiB

URL	Transfer Size	Est Savings
www.sncf-connect.com/widget/web-widgets-v1.0.0.js	303.7 KiB	154.1 KiB
/pagead/managed/js/gpt/m202604030101/pubads_impl.js?cb=31...	182.6 KiB	128.3 KiB
www.datadoghq-browser-agent.com/eu1/v6/datadog-rum.js	57.9 KiB	46.3 KiB
/sdk/c8e2e67c354c0d6dec2981e079061b37f6a1f337/modern/sdk....	89.3 KiB	33.9 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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 28.6 KiB

URL	Transfer Size	Est Savings
	20.7 KiB	16.4 KiB
www.sncf-connect.com/themes/custom/mercure_sb/dist/css/main.css?tcih7w	17.8 KiB	12.2 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL
SNCF Connect coeur et mains `div.didomi-popup-container > div.didomi-popup-view > div.didomi-popup-notice-logo-container > img.didomi-popup-notice-logo`	www.sncf-connect.com/didomi-popin-handshake.svg
Télécharger dans l'app store (nouvel onglet) `div.vsc-push-store__content > div.vsc-push-store__links > a.vsc-button > img`	www.sncf-connect.com/#
Disponible sur google play (nouvel onglet) `div.vsc-push-store__content > div.vsc-push-store__links > a.vsc-button > img`	www.sncf-connect.com/#
div#block5_store > div.vsc-push-store__wrapper > div.vsc-push-store__image > img `div#block5_store > div.vsc-push-store__wrapper > div.vsc-push-store__image > img`
Apple Pay `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
CB `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
Visa `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
Mastercard `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
American Express `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
Paypal `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
ANCV `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
Alma `div#block-mercure-sb-vsc-payment-methods > ul.vsc-footer__list > li > img`	www.sncf-connect.com/#
Allianz Travel `ul.vsc-footer__list > li > a.vsc-footer__link > img`	www.sncf-connect.com/#
Railteam (nouvel onglet) `ul.vsc-footer__list > li > a.vsc-footer__link > img`	www.sncf-connect.com/#
Télécharger dans l'app store (nouvel onglet) `ul.vsc-footer__list > li > a.vsc-button > img`	www.sncf-connect.com/#
Disponible sur google play (nouvel onglet) `ul.vsc-footer__list > li > a.vsc-button > img`	www.sncf-connect.com/#

More information about the performance of your application. These numbers don't directly affect the Performance score.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Element	Layout shift score
Continuer sans accepter → Votre vie privée est notre priorité Avec votre accor… `div#didomi-host > div.notranslate > div#didomi-popup > div.didomi-exterior-border`	0.096
Recherchez une destination, un trajet, un numéro de train... `article.node > div.vsc__node-content > div#universal-search > div.vsc-universal-search__heading`	0.005

●Time to Interactive 2.1 s

●Max Potential First Input Delay 110 ms

●Document request latency

●Optimize DOM size

●Font display

●Forced reflow

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 1,704 KiB

●User Timing marks and measures 3 user timings

●JavaScript execution time 0.6 s

●Minimizes main-thread work 1.2 s

●Avoid long main-thread tasks 3 long tasks found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 40 ms

●Server Backend Latencies 30 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 60 ms

○INP breakdown

○Avoid non-composited animations

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.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Train `ul.vsc-scroller__wrapper > li.vsc-scroller__item > a.vsc-button-link > span`
Taxi/VTC `ul.vsc-scroller__wrapper > li.vsc-scroller__item > a.vsc-button-link > span`

These are opportunities to improve the legibility of your content.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●Input buttons have discernible text.

●Form elements have associated labels

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●`button`, `link`, and `menuitem` elements have accessible names

●ARIA attributes are used as specified for the element's role

●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links have a discernible name

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●`[lang]` attributes have a valid value

●Heading elements appear in a sequentially-descending order

●Document has a main landmark.

●Deprecated ARIA roles were not used

●All heading elements contain content.

●Uses ARIA roles only on compatible elements

●Identical links have the same purpose.

●Elements with visible text labels have matching accessible names.

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

○`[role]`s are contained by their required parent element

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○`<input type="image">` elements have `[alt]` text

○Links are distinguishable without relying on color.

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`<video>` elements contain a `<track>` element with `[kind="captions"]`

○Tables have different content in the summary attribute and `<caption>`.

○Image elements do not have `[alt]` attributes that are redundant text.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

100

Best Practices

General

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Map URL
www.sncf-connect.com/widget/web-widgets-v1.0.0.js
www.sncf-connect.com/sdk/sdk-v1.10.0.js	www.sncf-connect.com/sdk/sdk-v1.10.0.js.map

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No browser errors logged to the console

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

100

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.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links have descriptive text

●Links are crawlable

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

○robots.txt is valid