A website update can change an experience that previously worked for a visitor. Accessibility checks therefore belong in the update process, not only in a one-time audit.
W3C explains that no tool alone can determine whether a site meets accessibility standards. Knowledgeable human evaluation is necessary. A screenshot comparison adds useful visual evidence, but it cannot establish WCAG conformance.
Define the journeys to evaluate
Choose the tasks visitors need to complete: finding information, navigating a menu, completing a form or reaching support. Include the states within each task, such as an expanded menu, validation error or confirmation message.
Keep a checklist that records the page, task, expected behavior, test method and person reviewing the result. A homepage screenshot alone does not represent the accessibility of the whole journey.
Use dedicated evaluation and manual checks
Choose accessibility evaluation tools for the checks they actually perform. W3C's tool selection guidance can help frame that choice. Keep tool findings separate from issues discovered through manual evaluation.
For a changed form, for example, review keyboard access, focus behavior, labels, error identification and the resulting task experience with appropriate assistive technology. Record the environment used and the observed issue so another reviewer can reproduce it. A visual baseline cannot tell you whether a label is programmatically associated with its input.
Use screenshots to prompt a closer look
Visual monitoring may draw attention to a changed layout, missing visible control or unexpected overlay. When a difference appears, review its effect on the task and run the relevant accessibility checks.
Visual Sentinel compares page captures. It should not be described as automatically auditing ARIA semantics, alternative text, language attributes or WCAG conformance. A page that looks unchanged can still have a broken keyboard interaction. A page that looks different may remain accessible.
Include accessibility in change approval
For each release, identify the affected journeys and repeat their checks. Record issues, ownership and the conditions for accepting the change. Review a new screenshot baseline after accepting the page, not before investigating an unexpected difference.
Track practical outcomes: issues found before release, unresolved barriers, repeated regressions and time to verify a fix. Use your own records to judge whether the process is catching regressions before release.
Explain monitoring honestly
If you provide website care to clients, distinguish a visual change report from an accessibility evaluation report. State the pages, tasks, methods and limitations of each service. This helps clients understand what was checked and what work remains.
Use visual monitoring as one source of change evidence alongside the accessibility methods your website requires. Review the methodology before deciding whether it fits your workflow.
Run a website of your own? Read about keeping watch over your own website, so an alert tells you when something on it breaks.
Check your site while you read
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Check a site freeCommon questions
Does Visual Sentinel certify WCAG conformance?
No. Screenshot comparison shows when a page looks different; WCAG conformance needs an accessibility evaluation.
Can a screenshot catch an accessibility regression?
It may reveal a visible change worth investigating. Many accessibility properties require other evaluation methods.
What should an accessibility change record contain?
Record the task, environment, observed barrier, reproduction steps, responsible person and verification of the fix.
