Automated Tools for Testing Accessibility
To find out if your website is accessible, automated tools are a good place to start. Automated tools crawl a website and flag errors based on the Web Content Accessibility Guidelines (WCAG). Many tools also provide guidance on how to fix the issues. These tools save time for both developers and content creators, and they often catch errors that might not be obvious.
While automated tools are a huge help in accessibility testing, they can’t catch every error, since they can’t understand context or evaluate content quality. So after you’ve done a first pass with automated tools, you’ll need to follow up with manual testing to make sure your website is inclusive and accessible.
There are hundreds of helpful accessibility tools, so we’ve selected a few of our favorites that we recommend to evaluate the accessibility of websites.
Siteimprove
Harvard-Licensed Tool to Check Accessibility
- Breaks down accessibility issues into prioritized, manageable tasks
- Runs automated Accessibility and Quality Assurance checks
- Tracks and reports progress towards accessibility compliance
- Provides guidance and practical recommendations
Getting Started with Siteimprove
- Introduction to Siteimprove
- Accessibility interactive tutorial
- Quality Assurance: Broken links and misspellings
- Register for Measuring Accessibility with Siteimprove, a brief overview of the platform led by Digital Accessibility Services (DAS)
Free Automated Tools
Comprehensive testing
These bring together a wide range of specific tools to check a variety of issues on a webpage, and can be useful for both content creators and developers.
- WAVE Accessibility Evaluation Tool by WebAIM, available for Chrome, Firefox, and Microsoft Edge.
- Siteimprove Accessibility Checker extension, check single pages including password-protected pages.
- axe DevTools by Deque, Chrome extension, must be used in “Inspect” mode.
- Accessibility Insights for Web by Microsoft, extension includes some automated checks, visualizing Tab stops, a guide for manual assessments, and can save a report.
- ANDI (Accessible Name & Description Inspector): a "favelet" or "bookmarklet," not an extension, that will provide automated detection of accessibility issues, reveal what a screen reader should say for interactive elements, and give practical suggestions.
Checking specific aspects of code and content
- HeadingsMap for Chrome or HeadingsMap for Firefox generates a document outline with headings.
- Nu HTML Checker, an HTML validator from W3C. Note that valid code does not on its own guarantee accessibility, but invalid code can cause accessibility problems.
- Photosensitive Epilepsy Analysis Tool (PEAT) checks the rate of flickering and flashing content in videos (Windows only).
Checking color contrast
- Contrast Checker by WebAIM, includes lightness sliders to adjust the colors to ones with sufficient contrast.
- Colour Contrast Analyser by The Paciello Group, a separate application that can select colors using an eyedropper tool.
- Contrast Ratio by Lea Verou, calculates a contrast ratio range when both colors include translucency (alpha channel). Color values are in the page address bar, so they’re easy to bookmark and share.