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What is the Accessibility Score?

Jennifer Chadwick avatar

Note: This article refers to our old accessibility product. Information on our latest Accessibility product can be found in Learn more about Accessibility NextGen and Accessibility NextGen: Understanding the revised DCI® accessibility score.

Siteimprove performs a combination of automated and semi-automated accessibility checks in reference to a selection of Web Content Accessibility Guidelines (WCAG) success criteria.

Your Accessibility Score is a measure of how well your site performs against the automated Siteimprove accessibility checks.

Your Accessibility Score contributes to your overall Digital Certainty Index® (DCI®) Score.

The Accessibility Score can be accessed on the Accessibility Overview page for a selected site.

Screenshot of the Accessibility overview page showing Score details, Overall score, and the Accessibility Score progress graph.

Is the Accessibility Score a compliance score?

No. WCAG compliance cannot be measured with automated checks alone, therefore, your Accessibility score does not represent how compliant your website and its content are with regards to WCAG.

Automated accessibility testing is an integral and strategic method for maintaining an accessible web presence. A large number of techniques used to measure WCAG success criteria can be automated. For example: whether an image tag contains an alt attribute to provide a description for the image.

Additionally, manual testing carried out by experts is required to accurately measure WCAG compliance for those success criteria that must be verified by human interaction.  For example: whether the elements on the page are accessible by keyboard only (no mouse).

How do I improve my Accessibility Score?

You can improve your Accessibility Score by earning points for fixing issues that belong to one of the three issue categories listed under “Score details”:

  • No automatically detected Errors
  • No automatically detected Warnings
  • Proportion of pages with low Error rate

For more information on how points are achieved see the article "Accessibility score clarification".

What do the Accessibility Score categories mean?

Errors: automatically determined failures to meet success criteria in the Web Content Accessibility Guidelines (WCAG).

Warnings: automatically determined failures to meet best practices in the Web Content Accessibility Guidelines (WCAG).

Proportion of pages with low Error rate: number of pages with a single Error or Warning.

Learn more about understanding Techniques for WCAG Success Criteria.

What is the Accessibility Score weighting for each issue category?

Category Score Weighting
Errors High
Warnings Low
Pages with low Error rate Medium

What does the Accessibility Score not include?

Reviews (potential issues)

The Accessibility Score does not include issues categorized Reviews.

Screenshot from platform showing Levels of Conformance and Severity
 and highlighting reviews

Reviews: Potential failures to meet best practices or success criteria in the Web Content Accessibility Guidelines (WCAG), which can only be verified with a manual inspection.


PDFs with accessibility issues do not impact your sites Accessibility score.

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