Official foundations
Standards bodies, official documentation and public authorities are used as primary reference points.
Web resources
Performance, accessibility and quality
Quality tools reveal speed, accessibility and stability issues, but no score replaces a real person completing a task. Compare lab and field data when the latter is available.
Measure one page on a phone, then complete a task by keyboard and with larger text. Link findings to a specific component or piece of content before fixing them.
AI-generated illustration
Editorial method
A directory made to be useful, not merely long.
Each entry has a clear role and an official destination. The catalogue avoids link farms, copied descriptions and artificial rankings.
Professional tools
Established services are grouped by actual use: building, hosting, measuring, securing, publishing or promoting a website.
Independent reading
Inclusion is editorial and unpaid. A listing does not imply a partnership or guarantee.
Compare on three practical questions
| Criterion | Question to resolve |
|---|---|
| Test type | Does the result come from a laboratory test, field data or human assessment? |
| Journey | Do contact, search and navigation remain usable with a keyboard and on mobile? |
| Priority | Which problem blocks a user and which fix can be verified? |
Keep a short decision record: requirement, source, observed result and unresolved point. Test the same task with each candidate instead of comparing marketing lists of features.
Search and filter
Official starting points for this topic
Compare their role and documentation before selecting a tool. Inclusion is not a ranking.
44 resources displayed
The link restores the search and filters, including resources selected for comparison.
No resource matches these filters. Try a broader search.
Compare up to three resources
Select resources from the cards below. Compare their role and practical use, then verify current terms, costs, data export and support on official websites. Geographical origin describes the publisher; it does not establish where your data will be hosted.
No resource selected.
Google guidance on Web performance, accessibility and best practices.
Use it for : Connect performance or accessibility guidance to a measurement on your pages.
Apply it to a project
web.devVisit official website
Documentation for the Chrome browser, DevTools and Web platform.
Use it for : Reproduce an issue in the browser and record the test steps.
Apply it to a project
developer.chrome.comVisit official website
Performance analysis based on Lighthouse and available field data.
Use it for : Separate field and lab data, then check the relevant URL and device before prioritising fixes.
Apply it to a project
pagespeed.web.devVisit official website
Automated auditing for performance, accessibility, SEO and best practices.
Use it for : Use diagnostics to find reproducible causes and compare tests under similar conditions.
Apply it to a project
developer.chrome.comVisit official website
Detailed page-load testing from multiple devices and locations.
Use it for : Inspect loading and network waterfall for a defined scenario and location.
Apply it to a project
webpagetest.orgVisit official website
Speed reports, Web metrics and loading timelines.
Use it for : Read loading details rather than treating the score as a verdict.
Apply it to a project
gtmetrix.comVisit official website
HTML markup validation against Web rules.
Use it for : Fix HTML errors at the source, then check several templates.
Apply it to a project
validator.w3.orgVisit official website
Validation of CSS stylesheets.
Use it for : Inspect relevant errors without confusing a warning with a visible defect.
Apply it to a project
jigsaw.w3.orgVisit official website
Browser compatibility tables for Web technologies.
Use it for : Check feature support for the browsers used by the intended audience.
Apply it to a project
caniuse.comVisit official website
Website and application testing on real browsers and devices.
Use it for : Replay an important journey on priority devices and browsers.
Apply it to a project
browserstack.comVisit official website
Automated digital accessibility testing tools.
Use it for : Pair automated findings with human review of the journey.
Apply it to a project
deque.comVisit official website
Visual evaluation of accessibility issues on a Web page.
Use it for : Review alerts in context, then add keyboard, screen-reader and journey-comprehension checks.
Apply it to a project
wave.webaim.orgVisit official website
Resources, training and tools dedicated to Web accessibility.
Use it for : Read an accessibility method, then apply it to a real page.
Apply it to a project
webaim.orgVisit official website
Image compression and comparison directly in the browser.
Use it for : Compare image size and appearance before selecting a format.
Apply it to a project
squoosh.appVisit official website
Online compression for common Web image formats.
Use it for : Inspect output detail and file size before replacing an image.
Apply it to a project
tinypng.comVisit official website
French evaluation of a Web page’s environmental footprint.
Use it for : Use the indicator to compare pages, then inspect technical causes.
Apply it to a project
ecoindex.frVisit official website
French-language resources on digital sustainability and eco-design.
Use it for : Relate a sustainability recommendation to site measurement data.
Apply it to a project
greenit.frVisit official website
Official patterns and examples for designing accessible interactive components with ARIA.
W3C WAI — ARIA Authoring Practices Guide · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Compare the keyboard behaviour of an interactive component with a documented pattern.
Apply it to a project
w3.orgVisit official website
W3C list of accessibility evaluation tools to complement with human testing.
Use it for : Select audit aids, then manually review findings and user journeys.
Apply it to a project
w3.orgVisit official website
Documentation for the critical path, metrics, resources and performance measurement APIs.
Use it for : Connect a slow metric to resources, rendering and interactions on the affected page.
Apply it to a project
developer.mozilla.orgVisit official website
Reference for LCP, INP, CLS and their interpretation in real user experience.
Use it for : Distinguish lab measurements from real-user data where available.
Apply it to a project
web.devVisit official website
Guide to measuring and improving interaction responsiveness with INP.
Use it for : Inspect slow interactions on pages where visitors actually need to act.
Apply it to a project
web.devVisit official website
Documentation for public field data used to observe real-world Chrome experience.
Use it for : Consult available field data before interpreting a single test score.
Apply it to a project
developer.chrome.comVisit official website
Reference for Lighthouse audits and their limits when diagnosing a page in the lab.
Use it for : Use diagnostics to locate a cause, then verify the effect on a real task.
Apply it to a project
developer.chrome.comVisit official website
Structured methodology for defining scope, selecting a representative sample and documenting a WCAG evaluation.
Use it for : Prepare the sample and method before concluding on accessibility across a set of pages.
Apply it to a project
w3.orgVisit official website
Harmonized test rules for automatically or semi-automatically evaluating accessibility requirements.
Use it for : Understand what an automated rule checks and what remains outside its scope.
Apply it to a project
w3.orgVisit official website
Documentation for recording and analyzing rendering, long tasks, interactions and bottlenecks.
Use it for : Record a slow interaction to find blocking tasks and rendering work.
Apply it to a project
developer.chrome.comVisit official website
Reference for DevTools features covering the accessibility tree, contrast and computed properties.
Use it for : Inspect an element’s exposed properties, then test its keyboard use.
Apply it to a project
developer.chrome.comVisit official website
W3C tutorial on labels, instructions, validation and messages that make forms more accessible.
Use it for : Compare a real form with examples of labels, errors and confirmations.
Apply it to a project
w3.orgVisit official website
Official examples for clearly communicating success or errors after a form submission.
Use it for : Compare a real form’s errors and confirmations with the W3C accessibility examples.
Apply it to a project
w3.orgVisit official website
Public digital ecodesign framework with criteria, verification methods and a declaration for documenting service design choices.
Use it for : Assess applicable criteria and retain evidence; the progress score does not measure a carbon footprint.
Apply it to a project
arcep.frVisit official website
Reference for timed text tracks used for captions and descriptions.
Use it for : Compare the track with video, languages and necessary audio information.
Apply it to a project
developer.mozilla.orgVisit official website
Reference for font display strategies according to download and availability.
Use it for : Observe states before and after loading with a fallback font.
Apply it to a project
developer.mozilla.orgVisit official website
W3C tutorial on data tables and associations between cells and headers.
W3C WAI — Tables tutorial · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Test a real table with headings, caption and suitable navigation.
Apply it to a project
w3.orgVisit official website
WAI guidance for preparing accessible audio and video media.
Use it for : Plan necessary text and audio information during production.
Apply it to a project
w3.orgVisit official website
WAI overview of accessibility evaluation methods and steps.
Use it for : Define scope and human checks before interpreting an automated score.
Apply it to a project
w3.orgVisit official website
API observing changes in an element’s intersection with a reference area without a continuous scroll loop.
MDN Intersection Observer · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Start visual work when a component approaches the relevant visible area.
Apply it to a project
developer.mozilla.orgVisit official website
HTML element for modal or non-modal dialogs with native behaviour to verify within the user journey.
MDN HTML Dialog · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Check opening, closing and focus in a confirmation dialog.
Apply it to a project
developer.mozilla.orgVisit official website
HTML disclosure element pairing collapsible content with a summary label without a dedicated script.
MDN HTML Details · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Show supplementary information without hiding essential decision criteria.
Apply it to a project
developer.mozilla.orgVisit official website
HTML attribute indicating expected information types and hints for automatic form filling.
MDN HTML Autocomplete · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Reduce repeated typing while retaining clear labels and validation.
Apply it to a project
developer.mozilla.orgVisit official website
Interface receiving new browser performance timeline entries for supported entry types.
MDN PerformanceObserver · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Observe performance without assuming every browser exposes identical measurements.
Apply it to a project
developer.mozilla.orgVisit official website
Documentation of network timings and sizes exposed by performance entries for loaded resources.
MDN Resource Timing · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Identify a slow resource while distinguishing network, compression and cache.
Apply it to a project
developer.mozilla.orgVisit official website
API for named markers and measured intervals corresponding to application-specific steps.
MDN User Timing · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Measure the time between an action and its genuinely usable result.
Apply it to a project
developer.mozilla.orgVisit official website
Explanation of back/forward navigation cache, which may restore a page and its state without a full reload.
web.dev Back/forward Cache · Source consulted
The date applies to the linked document, not to a review of every service feature.
Use it for : Check returning to a list after a detail page and guard against stale state.
Apply it to a project
web.devVisit official website
Choose a starting point
What each category helps you decide.
These examples illustrate uses, not rankings or endorsements. Verify each provider’s current documentation and terms before a decision.
Performance, accessibility and quality
Quality tools reveal speed, accessibility and stability issues, but no score replaces a real person completing a task. Compare lab and field data when the latter is available.
Questions to check- Measure different page families and devices.
- Connect each finding to a cause and an affected journey.
A practical use : Measure one page on a phone, then complete a task by keyboard and with larger text. Link findings to a specific component or piece of content before fixing them.
What this cannot prove : A lab score varies with its environment and cannot describe all visitors. Automated checks do not cover every accessibility barrier.
Examples : web.dev · PageSpeed Insights
Related guide : Test website accessibility through real tasks
Troubleshooting methods
Quality tools help locate a defect; validation concerns a task that can actually be completed. Preserve the device, width, context and actions for each trial. These situations connect a score or file to an observable difficulty.
A good score conceals a keyboard barrier
- What you observe
- An automated report is reassuring, but a menu, filter or window closure prevents task completion using a keyboard.
- Before drawing a conclusion
- Automated and manual checks do not cover identical barriers. A successful report does not replace observing the task.
- Verification step
- Complete the action from the beginning with a keyboard. Record focus order, visibility, announced state and a way out of the component. Connect each barrier to the relevant check and retest after correction.
A small photograph still downloads a large file
- What you observe
- The image occupies little space on a mobile page, but the browser retrieves a version much larger than its display warrants.
- Before drawing a conclusion
- Reducing CSS width changes presentation, but not necessarily the transferred file. Offered variants and the browser’s actual selection need inspection.
- Verification step
- Compare displayed width, resource dimensions, the actual loaded file and transferred size. Test several viewport widths and screen densities. Also check cropping and alternative text after optimisation.
Lab results and user feedback disagree
- What you observe
- Your tests are fast, while some visitors report slow opening or elements moving during reading.
- Before drawing a conclusion
- A local trial reflects its own conditions. Visitors may use different devices, networks, caches or stages of a task.
- Verification step
- Reproduce a first load, slower connection and representative page with long content. Compare available field data while preserving its period and coverage; do not claim a universal experience from one trial.
Further documentation
Keep useful data when changing tools
Before making a resource part of website operations, plan for updates and an exit too. These checks concern your trial results without assuming features or prices of a particular plan.
Keep test conditions
Retain URL, viewport, browser, date and measurement mode. A lab result without conditions cannot be compared reliably with another run.
Export useful defects
For each retained defect, keep steps, expected result and impact. A score disappearing from a tool does not prove a fix.
Change methods
Repeat representative manual checks. A tool update can change its rules even when the page is unchanged.
Transparency
Suggest a resource or correction
Editorial scope and third-party websites
This non-exhaustive directory had its data consistency and links checked on 2 October 2026. Some websites restrict automated checks. It contains external links to independent websites. Their availability, content, prices, cookies and terms may change. Française du Numérique does not control them and receives no commission for their inclusion.
Directory questions
Selection, independence and updates.
The editorial selection prioritises primary and official sources, established standards bodies, widely used professional tools, specialised media and active communities that are directly relevant to creating, operating, securing or promoting websites. An entry should have a clear purpose, an identifiable publisher and an official destination. The catalogue is independent, non-exhaustive and does not attempt to rank every available provider. Inclusion may be reconsidered when a resource closes, changes purpose, becomes misleading or no longer offers enough practical value. Review dates indicate when the catalogue was last checked as a whole, not a guarantee that every external page remains unchanged afterwards. Visitors should therefore confirm current pricing, terms, security and suitability on the third-party website before relying on a service.
No. A directory entry is a practical reference, not a certification, partnership, security audit or commercial endorsement. The listed organisations remain responsible for their products, content, prices, availability, cookies, personal-data practices and contractual terms. A resource may be useful for one project and unsuitable for another because requirements, jurisdiction, budget and technical capacity differ. Française du Numérique does not receive a commission for inclusion in this editorial directory. Before creating an account, purchasing a service or transferring data, visitors should review the official documentation, current terms, support arrangements, export options and relevant independent evidence. When the decision carries legal, financial or security consequences, an appropriately qualified assessment may also be necessary.
Yes. The search field checks resource names and editorial topics, while filters narrow the catalogue by category, geographical origin and resource type. Filtering and sorting take place locally in the browser, so the text entered in the directory search is not sent to a separate search provider. Combining several filters may produce no result even when a useful resource exists in a neighbouring category; in that case, remove one filter or try a broader term. The catalogue descriptions are deliberately concise and cannot represent every feature offered by a third party. Open the official website to confirm capabilities, documentation and current conditions before making a decision.
Use the contact page and provide the resource name, official URL, publisher, relevant category and a short explanation of its value for web professionals or project owners. For a correction, identify the entry and the information that appears inaccurate or outdated, ideally with a primary source. Suggestions are reviewed before publication and may be declined when the destination lacks a clear publisher, duplicates an existing entry, is primarily promotional, creates avoidable risk or falls outside the directory scope. Submission does not guarantee inclusion or a particular position, and paid placement is not offered through this editorial process.
Record the URL, viewport width and height, zoom level, language and preceding steps. A screenshot alone may not describe the cause. Include the expected result and affected element, then verify the fix in the same context.
Start with the changed component and page families sharing its rules. Cover mobile, desktop, long text and relevant languages. Broaden checks when the change affects a global rule, causes a regression or leaves uncertainty about other templates.
Compare using observable evidence
Before choosing a resource, run a limited trial using the same data and task. Keep the outcome and its limitations rather than a ranking based on familiarity.
Run the same task on mobile, with a keyboard and using the chosen inspection tools. Keep page, device, conditions and observed obstacle. An automated score does not replace a journey check; connect each issue to a tested correction.
Use precise terms
Two distinctions before comparing resources
An image’s meaning and the version actually displayed concern different aspects of quality.