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Classifying and prioritising accessibility bugs

At work the other day we were discussing accessibility bugs. How do we know when a bug is genuine, how important it is? Two big ways came to mind


One way to classify accessibility bugs is by Severity: the impact on the user.

  1. The issue stops users from accessing content or completing a task. We call that a Critical Severity issue. These are important and urgent. Common Critical issues:
    • Functionality is not available from the keyboard.
    • Form fields don’t have an accessible name.
    • Links or buttons don’t have an accessible name (often because of missing alternative text on an icon link or button).
  2. The issue causes problems for users. Depending on how big the problems are, we call that a High, Medium, or Low Severity issue.
    • High Severity issues are important, but less urgent than Critical issues.
    • Medium and Low Severity issues are less important and less urgent than Critical issues (but we should still fix them when we can!).

WCAG Success Criteria Level

Another way to classify bugs is by the WCAG Success Criteria Level.

  1. Issues that fail a Level A SC are important and urgent. Level A is minimum compliance
  2. Issues that fail a Level AA SC are important and less urgent. Level AA is acceptable compliance, and most people’s target compliance level.