axe - Web Accessibility Testing by Deque Systems Inc.

Accessibility Checker for Developers in Firefox

Accessibility checker for WCAG 2 and Section 508 accessibility. Find accessibility defects on your website or web application by using the axe™ Firefox add-on. Drop the axe on your accessibility defects!

The axe accessibility checker for Firefox is a fast, lightweight accessibility testing tool that returns zero false positives. It only tests for accessibility issues that can be accurately detected via automation, and it only tests for components that actually exist on the page or application you’re testing.

The axe Firefox add-on utilizes the axe open source JavaScript library developed by Deque Systems – the third generation of accessibility rules for HTML-based user interfaces. The axe library differentiates itself from other approaches and rules repositories in the following ways:

1. It works on all modern browsers
2. It supports in-memory fixtures, static fixtures, integration tests and iframes of infinite depth
3. It has zero false positives (bugs notwithstanding)
4. It is open source
5. It is actively supported by a major accessibility vendor
6. It is designed to work with whatever tools, frameworks, libraries and environments you have today
7. It is designed to be integrated into your existing functional/acceptance automated tests
8. It automatically determines which rules to run based on the evaluation context
9. It is highly configurable