Skip to main content
U.S. flag

An official website of the United States government

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.


Color tools

Color impairment

  • Color Oracle is a desktop application for simulating color impairment on your entire screen.
  • colourblind is another simulation tool similar to Daltonize, but with more options (protanopia, protanomaly, deuteranopia, deuteranomaly, tritanopia, tritanomaly, achromatopsia, and achromatomaly) in a single bookmarklet.
  • postcss-colorblind is a CSS build tool that modifies colors in your CSS to simulate four common impairment groups.

Accessibility review tools

These tools can be used to test sites for Section 508 and WCAG compliance in browser:

Autocomplete widgets

These JavaScript widgets produce HTML with ARIA autocomplete attributes:

Automated testing

Automated testing tools can help you find some of the more common accessibility mistakes quickly, however no automated tool can detect all accessibility issues. A recent experiment by the UK's Government Digital Service found that the best automated tools only caught about 40 percent of the errors on a test site; some of the most popular tools caught less than 20 percent. Whatever automated tool you use, be sure to also do manual testing.

These tools can be used in automated tests and with continuous integration tools to help you ensure that your sites remain accessible throughout the development process:

There are many other npm packages tagged wcag and a11y.

18F Accessibility

An official website of the GSA’s Technology Transformation Services

Looking for U.S. government information and services?