Web Accessibility Tools

This page contains a list of tools that can be used to evaluate the accessibility of web content. These tools are available under an open source licence unless otherwise noted. Inclusion in this list does not imply endorsement.

Note: most accessibility requirements, such as the WCAG success criteria and the requirements in EN 301 549, cannot be evaluated automatically.

Lists of Tools

Individual Tools

Code Checkers

The following tools are no longer being developed:

Contrast Checkers

Whether foreground and background colous have sufficient contrast is not something that you should try to “eyeball”. For example, red and green are strongly contrastly contrasting colour for people with normal colour vision but not for most people with colour vision deficiencies. There are many free tools that can help you check contrast, find colours with sufficient contrast or simulate certain colour vision deficiencies.

Most contrast analysis tools now support the contrast algorithm defined in the Web Content Accessibility Guidelines (WCAG) 2.0 and will tell you whether the contrast ratio pass at Level AA or at Level AAA. Some tools will also tell you whether the contrast meets the requirements defined in the Techniques For Accessibility Evaluation And Repair Tools (AERT) (August 2000). However, this document never went beyond the W3C working draft stage, and its contrast algorithm is explicitly marked as open to change.

Tools that simulate colour blindness try to approximate what people with colour vision deficiencies see; the output of these tools should not be interpreted as exact renditions of what these people see.

Articles on Checking Contrast

Accessible Colour Pickers

Colour Blindness Simulators

Articles about Automated Accessibility Evaluation

Developing Browser Extensions

Stylesheets for Finding Issues

Various Browser-Based Tools

Stylesheets, bookmarklets and other scripts for visualising specific markup features.

Browser Features and Extensions for End Users

Comparing or Benchmarking Evaluation Tools

Using Screen Readers for Accessibility Testing

Reporting Tools

Other Resources and Links