Accessibility Review


At Mozilla, accessibility is a fundamental part of our mission to ensure the internet is “open and accessible to all,” helping to empower people, regardless of their abilities, to contribute to the common good. Accessibility Review is a service provided by the Mozilla Accessibility team to review features and changes to ensure they are accessible to and inclusive of people with disabilities.

Do I Need Accessibility Review?

You should consider requesting accessibility review if you aren’t certain whether your change is accessible to people with disabilities. Accessibility review is optional, but it is strongly encouraged if you are introducing new user interface or are significantly redesigning existing user interface. Review should be requested both on the design side and on the engineering side.

When Should I Request Accessibility Review?

Generally, it’s best to request accessibility review as early as possible, even during the product requirements or UI design stage. Particularly for more complex user interfaces, accessibility is much easier when incorporated into the design, rather than attempting to retro-fit accessibility after the implementation is well underway.

The accessibility team has developed the Mozilla Accessibility Release Guidelines which outline what is needed to make user interfaces accessible. To make accessibility review faster, you may wish to try to verify and implement these guidelines prior to requesting accessibility review.

For design reviews, please allow at least a week between review request and expected-engineering-handoff. The deadline for engineering review requests is Friday of the first week of nightly builds for the release in which the feature/change is expected to ship. This is the same date as the PI Request deadline.

Requesting Design Review

Design review should be requested using the Accessibility Review Request workflow in the #accessibility slack channel. To access this workflow, click on the workflow link in the #accessibility slack channel header or in the links sidebar. You can also type /accessibility design review request from any channel or DM. Then, fill in the information requested.

Please complete the following self-review tasks before requesting review. Note: Some of the following links require SSO authentication.

  • Perform a contrast audit: Using a figma plugin that audits contrast, check your designs for color contrast sufficiency. Your designs should be at least “AA” rated in order to pass accessibility review. “AAA” is even better! If there are particular components that are difficult to adjust to meet “AA” standards, make a note in the figma file and the a11y team will provide specific guidance during review.

  • Add focus order and role annotations: Focus order annotations describe the behaviour a keyboard user should expect when navigating your design. Generally this follows the reading order. Note that we only care about focusable elements here (ie. links, buttons, inputs, etc.). Role annotations help screen readers and other assistive technologies identify the “kind” of component they’re navigating through. These mappings expose semantic information to the user. You can find a list of common roles here. You may want to use a figma plugin that annotates focus and roles for this process. You do not need to annotate every view in your design, pick those with the largest amount of new content.

  • Create Windows High-Contrast Mode (HCM) mockups: Our designs should be accessible to users running HCM. You can read more about how HCM affects color selection, and how to design for HCM. Using the “Night Sky” HCM palette, translate your designs into High Contrast. Remember, it’s important we use these colors semantically, not based on a desire for a particular aesthetic. Colors are labelled according to their uses – Background for page background, Button Text for button or control text, Selected Item Background for backgrounds of selected or active items, etc.. You do not need to mock up every view in your design, pick those with the largest amount of new content. You can find examples of previous HCM mock ups here. Where possible, we should rely on SVG’s and PNG’s for image content to increase adaptability.

Requesting Engineering Review

For an engineering-focused review, you submit a review request by setting the a11y-review flag to “requested” on a bug in Bugzilla and filling in the template that appears in the comment field. For features spanning several bugs, you may wish to file a new, dedicated bug for the accessibility review. Otherwise, particularly for smaller changes, you may do this on an existing bug. Note that if you file a new bug, you will need to submit the bug and then edit it to set the flag.

During the review process, the accessibility team will modify the a11y-review flag:

  • assigned: The review has been triaged by the team and an engineer has been assigned to the review. If the flag has been set on a bug filed specifically for the purposes of review (i.e., the bug does not have additional engineering work attached, and the bug is not a meta bug) the review assignee will assign the bug to themselves. Otherwise, they’ll comment on the bug so you know who they are :)

  • passed: Either no changes are required, or some changes are required but the accessibility team does not believe it is necessary to review or verify those changes prior to shipping. Generally, a review will not be passed if there are outstanding s2 or certain high impact s3 accessibility defects which should block the feature or change from shipping. However, despite their high severity, some s2 defects are trivial to fix (e.g. missing accessibility labels), so the accessibility team may elect to pass the review on the condition that these are fixed promptly.

  • changes required: Changes are required and the accessibility team will need to review or verify those changes before determining whether the accessibility of the feature or change is acceptable for shipping. It is the responsibility of the requesting engineering team to re-request accessibility review once changes are made to address the accessibility team’s initial round of feedback.

Phabricator Review Group

There is also an accessibility-frontend-reviewers group on Phabricator. This should generally only be used if:

  1. The patch is a change requested as part of an accessibility review as described above; or

  2. There is a very specific aspect of accessibility implemented in the patch and you would like the accessibility team to confirm whether it has been implemented correctly.

If you would instead like the accessibility team to assess whether a feature or change is sufficiently accessible, please request an accessibility engineering review as described above. Without this, the accessibility team will not have sufficient context or understanding of the change or how to test it, which is necessary to thoroughly assess its accessibility.


If you have any questions, please don’t hesitate to contact the Accessibility team:

  • #accessibility on Matrix or Slack

  • Email:

  • Please avoid reaching out to individual team members directly – containing review requests and questions in these channels helps us balance our workload. Thank you!