What is ASLint

ASLint is an Accessibility validation utility. It is designed and created by Cezary Tomczyk.

Couple of reasons why ASLint has been created:

  • To work with Single Page Applications model.
  • To provide simple explanation of the problem. At least that’s the goal.
  • To show what’s the impact on the business so you can focus on which problems has to be fixed first.
  • Easy plug-in into automation tests.


  • Verify accessibility of your content in real-time, including Single Page Applications.
  • Review results and determine the impact on the business.
  • Does not send content or data externally, so can be used for internal-only purposes.
  • Tests can be run asynchronously (without blocking the UI) or synchronously.
  • Provides code snippet to add to build pipeline (e.g. for automation tests) or developer console, or can run as a bookmarklet.
  • Easy locating issues on the page from the results using element detector or XPath
  • Color contrast recommendations
  • Provides checklist for things that can’t be tested automatically.
  • Provides WCAG level 1,2,3 and Section 508 tests.
  • Provides tests that aren’t included in WCAG or Section 508.
  • Provides option to emulate High Contrast Mode (experimental).
  • Every report contains:
    • explanation of issue,
    • what’s causing issue,
    • options to locate visible element or by XPath,
    • determine impact,
    • contains (if possible) links to external resources to get more details about the issue.

Get in touch

That’s not the end and ASLint will evolve.

Questions? Nice things to say? Criticisms? Contact me directly or use ASLint GitHub issue tracker