Free Website Accessibility Checker

What a website accessibility checker actually checks

A good accessibility checker inspects the rendered DOM of a page and tests it against the machine-detectable parts of the Web Content Accessibility Guidelines (WCAG). It is not a spell checker for design taste. It is a structured audit of whether assistive technology, such as screen readers, screen magnifiers, and keyboard navigation, can actually reach and understand your content.

AccessGuard groups findings into the categories that matter most in the real world. Color contrast confirms that text stands out enough from its background to be readable by people with low vision. Text alternatives check that meaningful images carry alt text and that decorative images are correctly hidden. Form labels verify that every input, checkbox, and select has a programmatically associated label so a screen reader can announce it. ARIA validation catches roles, states, and properties that are missing, invalid, or misused, which is one of the most common ways well-intentioned code breaks accessibility.

Beyond those, the scanner evaluates keyboard operability so that interactive elements can be reached and triggered without a mouse, and it reviews document structure: heading order, landmark regions, list markup, table headers, and a valid page language attribute. These structural signals are what let users skim, navigate by heading, and understand relationships between elements.

• Color contrast of text and interactive elements against their backgrounds
• Alt text on informative images and correct hiding of decorative ones
• Programmatic labels on form fields, buttons, and links
• ARIA roles, states, and properties used validly and only where needed
• Keyboard reachability, visible focus, and logical focus order
• Heading hierarchy, landmarks, lists, tables, and page language

The issues most sites fail on first

You are not starting from zero, and you are almost certainly not alone in the problems you find. The WebAIM Million analysis of the top one million home pages consistently shows that roughly 96 percent of detected errors fall into just six categories, and those same six have led the list for years.

Low contrast text is the single most common failure, detected on around 84 percent of home pages, followed by missing alt text on images, missing form labels, empty links, empty buttons, and missing document language. The encouraging part is that every one of these is either automatically detectable or clearly explained once a scanner surfaces it. A checker turns a vague worry into a concrete, prioritized punch list.

AccessGuard reports each issue with the specific element, the WCAG success criterion it relates to, and why it matters to a real user. That context is what separates a useful scan from a wall of red warnings, because it lets your team fix the highest-impact barriers first instead of chasing noise.

Automated scanning vs manual testing: know the difference

Automated tools are fast, repeatable, and honest about the things machines can measure, but they cannot judge everything. Industry testing shows automated scanners reliably catch somewhere between about 30 and 57 percent of WCAG issues depending on the tool and configuration. The rest require human judgment.

A machine can measure a contrast ratio, detect a missing label, or flag an invalid ARIA attribute with confidence. What it cannot reliably do is decide whether alt text is meaningful rather than merely present, whether reading order makes sense, whether a custom widget behaves correctly with a real screen reader, or whether an error message is genuinely understandable. Those are judgment calls that need a person, ideally one testing with actual assistive technology and keyboard-only navigation.

The practical takeaway is that a checker is your foundation, not your finish line. Run automated scans continuously to catch regressions and clear the high-volume issues, then layer manual review on your critical flows: sign up, checkout, search, and forms. Treat any tool, including AccessGuard, as the first and most efficient pass rather than a certificate of full compliance.

How to fix the issues a scan finds

Fixing accessibility issues is usually less work than teams expect, because most fixes are small, well-documented code changes rather than redesigns. The key is to work in priority order and to fix causes, not symptoms.

Start with contrast by adjusting text or background color values until they meet the WCAG ratio (generally 4.5 to 1 for normal text and 3 to 1 for large text). Add concise, descriptive alt text to informative images and mark purely decorative images so assistive tech skips them. Give every form control a real label using a label element or an accessible name, and make sure links and buttons contain descriptive text rather than an icon alone. For ARIA, the safest fix is often to remove unnecessary attributes and lean on native HTML elements, which are accessible by default. Then confirm keyboard access by tabbing through the page and watching for a visible focus indicator on every interactive element.

AccessGuard pairs each finding with developer fix guidance and code-level suggestions, and you can export a PDF report to share with designers, developers, or stakeholders. If your team wants the work done for you, VASTROX offers accessibility repair, WordPress maintenance, and web development support, plus a WordPress plugin to keep scanning as your site changes.

• Fix contrast first, it is the most common and often the quickest win
• Write meaningful alt text and hide decorative images
• Attach real labels to every form field, link, and button
• Prefer native HTML over ARIA, and remove invalid ARIA
• Tab through the page to confirm focus is visible and logical
• Re-scan after each change to confirm the fix and catch regressions

WCAG issue detection and EAA readiness signals

AccessGuard maps findings to WCAG 2.1 and 2.2 success criteria and surfaces European Accessibility Act (EAA) readiness signals so you can gauge where your site stands as regulatory expectations tighten across the EU. These signals help you prioritize and demonstrate good-faith progress to your team and stakeholders.

It is important to be clear about what this is and is not. AccessGuard provides an accessibility scanner, WCAG issue detection, EAA readiness signals, accessibility improvements, and developer fix guidance. It is not legal advice, and a passing scan does not guarantee legal compliance with the EAA, the ADA, Section 508, or any other law. Full conformance depends on manual testing, real assistive-technology validation, and often qualified legal review.

Use AccessGuard to move quickly and confidently in the right direction: find issues, understand them, fix them, and keep your site measurably more accessible over time. For questions of legal obligation, consult a qualified professional.

Frequently asked questions

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