Understanding the score and severity

Each page starts at 100. Every failing rule takes points off by severity (critical 10, serious 6, moderate 3, minor 1), scaled up gently by how many elements fail it. A site’s score is the average of its pages.

• Critical: blocks some people completely, such as a button with no name.
• Serious: makes a task very hard, such as low text contrast.
• Moderate: causes confusion or extra effort.
• Minor: a small annoyance.

A score of 100 means no automated check failed. It doesn’t mean the site is compliant: some requirements need a manual review.