Lighthouse Mobile

· 0 checks — Mobile 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.data.gouv.fr/nuxt_images/homepage/dvf@2x.png	0.0 ms	549.5 KiB
www.data.gouv.fr/nuxt_images/homepage/reuses@2x.png	0.0 ms	414.3 KiB
www.data.gouv.fr/nuxt_images/homepage/datasets@2x.png	0.0 ms	205.6 KiB
www.data.gouv.fr/nuxt_images/homepage/hero_7.png	0.0 ms	114.0 KiB
www.data.gouv.fr/fonts/Spectral-700-Italic.woff2	0.0 ms	89.2 KiB
www.data.gouv.fr/fonts/Spectral-400-Italic.woff2	0.0 ms	79.9 KiB
www.data.gouv.fr/nuxt_images/homepage/annuaire@2x.png	0.0 ms	51.9 KiB
www.data.gouv.fr/fonts/Marianne-800.woff2	0.0 ms	41.4 KiB
www.data.gouv.fr/fonts/Marianne-700.woff2	0.0 ms	41.4 KiB
www.data.gouv.fr/fonts/Marianne-500.woff2	0.0 ms	41.2 KiB
www.data.gouv.fr/fonts/Marianne-300.woff2	0.0 ms	40.7 KiB
www.data.gouv.fr/fonts/Marianne-400.woff2	0.0 ms	40.6 KiB
stats.data.gouv.fr/matomo.js	3600.0 s	50.3 KiB
www.data.gouv.fr/_ipx/_/illustrations/discussion.svg	60.0 s	19.6 KiB
www.data.gouv.fr/nuxt_images/organizations/minedu@2x.png	0.0 ms	9.8 KiB
www.data.gouv.fr/nuxt_images/organizations/insee@2x.png	0.0 ms	9.6 KiB
www.data.gouv.fr/nuxt_images/organizations/spf@2x.png	0.0 ms	8.3 KiB
www.data.gouv.fr/nuxt_images/organizations/googlemaps@2x.png	0.0 ms	7.4 KiB
www.data.gouv.fr/nuxt_images/organizations/cnil@2x.png	0.0 ms	6.7 KiB
www.data.gouv.fr/nuxt_images/organizations/wikimedia@2x.png	0.0 ms	6.4 KiB
www.data.gouv.fr/_ipx/_/illustrations/dataset.svg	60.0 s	5.4 KiB
www.data.gouv.fr/nuxt_images/organizations/liberation@2x.png	0.0 ms	5.2 KiB
www.data.gouv.fr/_ipx/_/nuxt_images/logo_text.svg	60.0 s	4.6 KiB
www.data.gouv.fr/nuxt_images/organizations/lemonde@2x.png	0.0 ms	4.3 KiB
/plugins/HeatmapSessionRecording/configs.php?idsite=109&t...	0.0 ms	286 B

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:0.141599] map[node:map[boundingRect:map[bottom:654 height:338 left:24 right:388 top:317 width:364] lhId:page-1-H1 nodeLabel:La plateforme des données publiques françaises path:1,HTML,1,BODY,0,DIV,7,DIV,1,DIV,3,DIV,0,SECTION,1,DIV,1,DIV,0,H1 selector:section.relative > div.relative > div.space-y-4 > h1.max-w-3xl snippet:<h1 class="max-w-3xl text-[54px] leading-[125%] font-extrabold text-new-primary text-…"> type:node] score:0.141599]]

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:97.489 source:map[type:text value:[unattributed]]]]

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-SECTION

nodeLabel: En ce moment : Données relatives aux élections Actualités : Suivi des sorties -…

path: 1,HTML,1,BODY,0,DIV,7,DIV,1,DIV,3,DIV,0,SECTION

selector: div.datagouv-components > div.group/layout > div > section.relative

snippet: <section class="relative py-8 sm:py-[200px] bg-cover bg-center" style="">

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

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
www.data.gouv.fr/_nuxt/entry.BmkqFH0c.css	187.4 KiB	1.1 s

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 > div.grid > div.bg-white > img.w-full `div > div.grid > div.bg-white > img.w-full`	www.data.gouv.fr/nuxt_images/homepage/dvf@2x.png	548.9 KiB	520.1 KiB
section > div.max-w-7xl > div.grid > img.sm:col-span-5 `section > div.max-w-7xl > div.grid > img.sm:col-span-5`	static.data.gouv.fr/images/7c/ed09e56c864b03afa2cfa1a05fcc5d.png	36.8 KiB	33.4 KiB
div > div.grid > div.bg-white > img.w-full `div > div.grid > div.bg-white > img.w-full`	www.data.gouv.fr/nuxt_images/homepage/annuaire@2x.png	51.6 KiB	30.7 KiB
Ministère de l'Éducation Nationale et de la Jeunesse `div.w-full > div.space-y-2.5 > div.grid > img.size-20`	www.data.gouv.fr/nuxt_images/organizations/minedu@2x.png	9.5 KiB	5.4 KiB
INSEE `div.w-full > div.space-y-2.5 > div.grid > img.size-20`	www.data.gouv.fr/nuxt_images/organizations/insee@2x.png	9.4 KiB	5.2 KiB

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

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
La plateforme des données publiques françaises `section.relative > div.relative > div.space-y-4 > h1.max-w-3xl`	0.142

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

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: 2.1 s 620.3 KiB

URL	Transfer Size	Est Savings
www.data.gouv.fr/_nuxt/DeWFfL1o.js	562.3 KiB	392.3 KiB
www.data.gouv.fr/_nuxt/CLIvgYrS.js	133.8 KiB	96.9 KiB
www.data.gouv.fr/_nuxt/BIpomotR.js	95.0 KiB	84.3 KiB
stats.data.gouv.fr/matomo.js	50.1 KiB	25.4 KiB
www.data.gouv.fr/_nuxt/CiafoMRz.js	37.3 KiB	21.4 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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Total CPU Time	Script Evaluation	Script Parse
Unattributable	1.8 s	801 ms	0.0 ms
www.data.gouv.fr/_nuxt/DeWFfL1o.js	641 ms	567 ms	8.7 ms
www.data.gouv.fr/	559 ms	5.2 ms	2.5 ms
stats.data.gouv.fr/matomo.js	514 ms	489 ms	17 ms
www.data.gouv.fr/_nuxt/entry.BmkqFH0c.css	266 ms	0.0 ms	0.0 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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Category	Time Spent
Script Evaluation	1.9 s
Other	1.2 s
Style & Layout	464 ms
Parse HTML & CSS	217 ms
Script Parsing & Compilation	46 ms
Garbage Collection	45 ms
Rendering	43 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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
Internal error.	Not actionable

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
www.data.gouv.fr/_nuxt/DeWFfL1o.js	563.0 KiB
www.data.gouv.fr/nuxt_images/homepage/dvf@2x.png	549.5 KiB
www.data.gouv.fr/nuxt_images/homepage/reuses@2x.png	414.3 KiB
www.data.gouv.fr/nuxt_images/homepage/datasets@2x.png	205.6 KiB
www.data.gouv.fr/_nuxt/entry.BmkqFH0c.css	187.4 KiB
www.data.gouv.fr/_nuxt/CLIvgYrS.js	136.8 KiB
www.data.gouv.fr/nuxt_images/homepage/hero_7.png	114.0 KiB
www.data.gouv.fr/_nuxt/BIpomotR.js	95.3 KiB
www.data.gouv.fr/fonts/Spectral-700-Italic.woff2	89.2 KiB
www.data.gouv.fr/fonts/Spectral-400-Italic.woff2	79.9 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
section > div.max-w-7xl > div.grid > img.sm:col-span-5 `section > div.max-w-7xl > div.grid > img.sm:col-span-5`	static.data.gouv.fr/images/7c/ed09e56c864b03afa2cfa1a05fcc5d.png
div.fr-header__brand > div.fr-header__service > a > img.inline `div.fr-header__brand > div.fr-header__service > a > img.inline`	www.data.gouv.fr/_ipx/_/nuxt_images/logo_text.svg
div.fr-footer__body > div.fr-footer__brand > a.fr-footer__brand-link > img.inline `div.fr-footer__body > div.fr-footer__brand > a.fr-footer__brand-link > img.inline`	www.data.gouv.fr/_ipx/_/nuxt_images/logo_text.svg
div.px-6 > div.w-full > div.space-y-2 > img.h-16 `div.px-6 > div.w-full > div.space-y-2 > img.h-16`	www.data.gouv.fr/_ipx/_/illustrations/dataset.svg
div.px-6 > div.w-full > div.space-y-2 > img.h-16 `div.px-6 > div.w-full > div.space-y-2 > img.h-16`	www.data.gouv.fr/_ipx/_/illustrations/discussion.svg

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

●Document request latency

●Optimize DOM size

●Font display

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Reduce unused CSS

●User Timing marks and measures 1 user timing

●Avoid long main-thread tasks 11 long tasks found

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 120 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 50 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.

ARIA

Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values. Learn more about valid values for ARIA attributes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.fr-header__brand > div.fr-header__brand-top > div.lg:!hidden > button.flex-none `div.fr-header__brand > div.fr-header__brand-top > div.lg:!hidden > button.flex-none`
div.fr-header__brand > div.fr-header__brand-top > div.lg:!hidden > button.flex-none `div.fr-header__brand > div.fr-header__brand-top > div.lg:!hidden > button.flex-none`

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.

Best practices

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html `html`

These items highlight common accessibility best practices.

○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 are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

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

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

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

●Elements use only permitted ARIA attributes

●Background and foreground colors have a sufficient contrast ratio

●Document has a `<title>` element

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

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

●Links are distinguishable without relying on color.

●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.

●Heading elements appear in a sequentially-descending order

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

○`[accesskey]` values are unique

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

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

○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 buttons have discernible text.

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

○Form elements have associated labels

○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.

○`[lang]` attributes have a valid value

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

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

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

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

○Elements with visible text labels have matching accessible names.

○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
www.data.gouv.fr/_nuxt/DeWFfL1o.js
www.data.gouv.fr/_nuxt/CLIvgYrS.js

●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 clickjacking with XFO or CSP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

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

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

○Document has a valid `rel=canonical`