About T-a11y

T-a11y (or Tally) is a tool built to simplify the process of accessibility testing.

We wanted to build an intuitive way for product teams to define “done” in a way that ensures accessible experiences work for everyone.

It uses Jekyll with a custom theme as a CMS and relies on markdown for entry creation.

Using T-a11y

Product owners, designers, developers or testers can use the checklist builder to collect testing instructions for web or native app components.

These testing criteria are displayed in markdown format for easy copying/pasting into project management tools like Jira.

Testing instructions includes:

  • How to test with keyboard
  • How to test with screeen reader
  • How to test with a screen reader on a mobile device
  • Link to the full entry

Each entry contains:

  • Video demos with recommended screen reader browser pairings
  • Code examples
  • Developer notes
  • Links to official WCAG and WAI-ARIA documentation


Here are some ways to contribute:

  • Add a concise video using a screen reader that’s not yet have covered.
  • Add an entry for a component that is not included.
  • Fix a typo or edit for consistent language.


T-ally is open sourced by T-Mobile and released under the Apache 2.0 License.