Guide for web agencies

What is accessibility regression testing?

A website can pass an automated accessibility check today and develop new detectable problems tomorrow. Accessibility regression testing means checking again after the site changes and comparing the new result with an earlier baseline.

Websites rarely stay still. A redesign changes colors and navigation. A plugin update changes markup. A content editor adds a new image, heading, button, or form. Any of those changes can introduce an accessibility problem even when nobody intended to touch accessibility.

The useful question is not only “What problems exist?”

For an agency maintaining client websites, another useful question is: “What changed since our last check?” That is the job of regression monitoring.

A practical agency workflow

1. Establish a baseline

Scan the public client site and save the detectable findings.

2. Scan after changes

Check again after releases, plugin updates, redesigns, or content work.

3. Review regressions

Prioritize new or worsened findings instead of treating every scan as an isolated event.

4. Fix and verify

Make the change, scan again, and confirm that the detectable problem improved.

What automated testing can—and cannot—tell you

Automated tools can reliably detect some classes of accessibility problems, such as certain color-contrast failures, missing accessible names, markup problems, and other machine-testable rules. They cannot determine whether an entire website is accessible to every person or establish legal compliance.

That is why regression monitoring is most useful as part of an accessibility process, alongside manual review and testing with assistive technologies when appropriate.

Why agencies may care

If you maintain several client websites, repeating one-off checks by hand is easy to forget. A stored baseline and scan history make accessibility maintenance more like uptime or security maintenance: something you can revisit after changes rather than rediscover from scratch.

Client-ready reports also make the work easier to communicate. Instead of handing a client raw scanner output, you can show what was tested, what needs attention, potential fixes, and whether the detectable result improved or regressed.

Try it on one client site

Barrier Beacon's Free plan lets you monitor one public site manually, keep scan history, and create a client report. No credit card is required.

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Barrier Beacon performs automated accessibility testing. Automated testing detects only some barriers and does not establish WCAG, ADA, or other legal compliance.