Web Accessibility Resources and Tools: Guidelines, Checklists, and Testing Solutions

A reference list of web accessibility tools, guidelines, and articles. Items marked Recommended are good starting points if you're new to accessibility or just want to focus on the essentials.

Checklist

Recommended: The Web Content Accessibility Guidelines (WCAG) (opens in a new tab): A detailed checklist based on WCAG 2.2, providing guidelines for creating accessible web content.

Guidance

Community resources

The A11Y Project is a community hub for practical accessibility resources.

Recommended: The A11Y Project (opens in a new tab): A community-driven resource that makes accessibility easier to understand and apply.
A11y Coffee (opens in a new tab): Practical tips and advice for web accessibility.
Inclusive Design Principles (opens in a new tab): A concise set of principles for designing inclusively.
The Accessibility Blog (GOV.UK) (opens in a new tab): Case studies and guidance from the UK Government Digital Service.

Official documentation

Mozilla's resource hub for developers tackling accessibility.

Recommended: MDN Accessibility (opens in a new tab): Mozilla's guide to web accessibility.
W3C Accessibility Standards Overview (opens in a new tab): An overview of W3C standards including WCAG, ARIA, and ATAG.
Understanding WCAG 2.0 (opens in a new tab): The official documentation explaining each WCAG guideline in detail.
Web Accessibility Tutorials (opens in a new tab): Step-by-step tutorials from the Web Accessibility Initiative (WAI).
ARIA in HTML (opens in a new tab): The official W3C guide to using ARIA roles and labels effectively.

Keyboard accessibility

WebAIM's guide explaining how to make sites navigable by keyboard.

Recommended: Keyboard Accessibility (opens in a new tab): A detailed walkthrough for making sites keyboard-friendly.
Keyboard (MDN) (opens in a new tab): Mozilla's reference for keyboard accessibility standards.
Accessibility features in Firefox (opens in a new tab): How Firefox supports users who rely on accessibility features.

Articles and case studies

Accessibility (opens in a new tab) (W3C): An overview of the standards that shape accessible web design.
Handling common accessibility problems (opens in a new tab): Mozilla's guidance on solving common accessibility issues.
Recommended: SSA 508 Test Method (opens in a new tab): The Social Security Administration's structured approach to accessibility testing.
What we found when we tested tools on the world's least-accessible webpage (opens in a new tab): GOV.UK's honest comparison of automated testing tools.
This guide is unreadable (opens in a new tab): A useful example of what poor accessibility looks like in practice.

Testing tools

No tool catches everything — automated tools typically find around 30-40% of accessibility issues. Use them alongside manual testing and keyboard navigation checks.

Browser extensions

Google Lighthouse offers audits for accessibility and site performance.

Recommended: Lighthouse (opens in a new tab): Built into Chrome DevTools. Audits accessibility, performance, SEO, and best practices.
axe DevTools (opens in a new tab): One of the most widely used accessibility testing libraries, available as a browser extension and via @axe-core/playwright for automated testing.

Microsoft's Accessibility Insights tool for detecting and fixing accessibility issues.

Recommended: Accessibility Insights (opens in a new tab): Microsoft's extension for finding and fixing accessibility issues, including a guided FastPass workflow.
ARIA DevTools (Firefox) (opens in a new tab) / (Chrome) (opens in a new tab): View missing ARIA labels, misused roles, and keyboard issues.
WAVE Evaluation Tool (Firefox) (opens in a new tab) / (Chrome) (opens in a new tab): WebAIM's browser extension for visual accessibility checks.

Contrast checkers

WebAIM's Contrast Checker makes colour contrast testing quick and simple.

Recommended: Contrast Checker (opens in a new tab): WebAIM's tool for checking text and background colour contrast ratios against WCAG thresholds.
Colour Contrast Accessibility Validator (opens in a new tab): Scans an entire page for contrast issues.

Visual testing and standalone tools

WebAIM's WAVE tool highlights accessibility issues visually on the page.

Recommended: WAVE (opens in a new tab): Overlays visual indicators on the page to show accessibility issues in context.
Pa11y (opens in a new tab): Command-line tool for automated accessibility testing. Useful in CI pipelines.
HTML_CodeSniffer (opens in a new tab): Detects code-level accessibility issues.
tota11y (opens in a new tab): A JavaScript bookmarklet that visualises accessibility errors directly on the page.
Asqatasun (opens in a new tab): Open-source tool for automated accessibility auditing.

— Karl