WCAG Accessibility Checker: How to Test Your Website for Free in 2026

Over 1.3 billion people worldwide live with some form of disability. If your website fails WCAG guidelines, you're not just excluding potential customers — you may be violating the law. An accessibility checker scans your site against the Web Content Accessibility Guidelines and flags issues so you can fix them before they become lawsuits or lost revenue.

This guide covers everything you need to know about WCAG compliance testing in 2026: what the guidelines require, how to test for free, which tools are best, and why accessibility and SEO are two sides of the same coin.

What Is WCAG?

WCAG stands for Web Content Accessibility Guidelines. Published by the World Wide Web Consortium (W3C), WCAG is the international standard for making web content accessible to people with disabilities — including visual, auditory, motor, and cognitive impairments.

The guidelines are organized around four core principles, often remembered by the acronym POUR:

• Perceivable: Users must be able to perceive the content. This means providing text alternatives for images, captions for video, and sufficient color contrast.
• Operable: Users must be able to operate the interface. All functionality must work with a keyboard, users must have enough time to read content, and nothing should cause seizures.
• Understandable: Content and interface behavior must be understandable. Text should be readable, pages should behave predictably, and users should get help avoiding and correcting errors.
• Robust: Content must be robust enough to work reliably with current and future assistive technologies, including screen readers and voice control software.

WCAG Conformance Levels: A, AA, and AAA

Each WCAG success criterion is assigned a conformance level that indicates how critical it is for accessibility:

Level A — Minimum Accessibility

Level A criteria address the most basic accessibility barriers. Without meeting Level A, your website is essentially unusable for many people with disabilities. Examples include:

• All non-text content (images, icons) has text alternatives
• All functionality is available from a keyboard
• Content doesn't flash more than three times per second
• Pages have descriptive titles
• Link purpose can be determined from link text

Level AA — The Standard Target

Level AA is what most laws and regulations require. It covers barriers that make the web difficult (but not impossible) to use. This is the level you should aim for. Key criteria include:

• Color contrast ratio of at least 4.5:1 for normal text, 3:1 for large text
• Text can be resized up to 200% without loss of content
• Images of text are avoided (use real text instead)
• Multiple ways to find pages within a site (navigation, search, site map)
• Consistent navigation and identification across pages
• Focus indicators are visible when navigating by keyboard

Level AAA — Enhanced Accessibility

Level AAA is the highest standard and is rarely required by law. Meeting AAA for an entire site is often not feasible, but you can target specific criteria. Examples include:

• Enhanced color contrast of 7:1 for normal text
• Sign language interpretation for prerecorded audio
• Extended audio descriptions for video
• Reading level of lower secondary education
• No timing limits on content interaction

Common Accessibility Issues (and How to Fix Them)

An accessibility checker will flag these issues automatically. Here are the most frequent WCAG violations found across the web:

1. Missing or Empty Alt Text

Screen readers cannot describe images without alt attributes. Every meaningful image needs descriptive alt text. Decorative images should use alt="" so screen readers skip them. In 2026, the WebAIM Million report still finds missing alt text on over 55% of home pages.

Fix: Audit all <img> tags. Write alt text that describes the image's function, not its appearance. "Red button" is bad; "Submit contact form" is good.

2. Insufficient Color Contrast

Low contrast between text and background makes content unreadable for users with low vision or color blindness. WCAG AA requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for text larger than 18px (or 14px bold).

Fix: Use a contrast checker tool. Avoid light gray text on white backgrounds — the single most common violation. Test with both light and dark mode if your site supports them.

3. Missing Form Labels

Form inputs without associated <label> elements leave screen reader users guessing what to type. Placeholder text alone is not sufficient because it disappears when the user starts typing and may not be announced by all screen readers.

Fix: Every <input>, <select>, and <textarea> should have a visible <label> with a matching for attribute, or be wrapped inside a <label> element.

4. Keyboard Navigation Failures

Users who cannot use a mouse rely on keyboard navigation. If interactive elements (buttons, links, menus, modals) are not focusable or operable via keyboard, these users are locked out. Custom JavaScript widgets are the most common offenders.

Fix: Use native HTML elements (<button>, <a>) instead of <div onclick>. Test by navigating your site with only the Tab, Enter, Escape, and arrow keys.

5. Broken Heading Hierarchy

Headings should follow a logical descending order: H1, then H2, then H3. Skipping levels (jumping from H1 to H3) confuses screen reader users who navigate by heading structure. This also hurts your SEO — search engines use heading hierarchy to understand content structure.

Fix: Each page should have exactly one H1. Sections use H2, sub-sections use H3. Never choose heading levels based on visual size — use CSS for styling.

6. Missing or Incorrect ARIA Attributes

ARIA (Accessible Rich Internet Applications) attributes help screen readers understand dynamic content. But incorrect ARIA is worse than no ARIA at all. Common mistakes include using role="button" without keyboard event handlers, or conflicting ARIA labels.

Fix: Follow the first rule of ARIA: if you can use a native HTML element with built-in semantics, do that instead. Only add ARIA when native elements are insufficient.

Legal Requirements: ADA, EAA, and Beyond

Accessibility is not optional in most markets. Here are the major laws you need to know:

United States: ADA and Section 508

The Americans with Disabilities Act (ADA) has been interpreted by federal courts to apply to websites since 2019. The Department of Justice published a final rule in 2024 requiring state and local government websites to meet WCAG 2.1 Level AA. Private businesses face ADA lawsuits regularly — over 4,000 federal web accessibility lawsuits were filed in 2025 alone.

Section 508 requires all federal government websites and technology to meet WCAG 2.0 AA (with updates moving toward WCAG 2.1).

European Union: European Accessibility Act (EAA)

The European Accessibility Act became enforceable in June 2025. It requires products and services sold in the EU — including websites, mobile apps, e-commerce platforms, and banking services — to meet WCAG 2.1 Level AA. This applies to businesses with 10+ employees or revenue exceeding 2 million euros.

Other Jurisdictions

• Canada: The Accessible Canada Act (ACA) requires WCAG 2.1 AA for federally regulated organizations
• UK: The Equality Act 2010 and Public Sector Bodies Accessibility Regulations require WCAG 2.1 AA
• Australia: The Disability Discrimination Act (DDA) references WCAG as the standard

How to Test Your Website for Accessibility

A thorough accessibility audit combines automated scanning with manual testing. Neither alone is sufficient.

Step 1: Run an Automated Accessibility Checker

Automated tools scan your HTML for detectable WCAG violations. They are fast and catch low-hanging fruit — missing alt text, contrast failures, missing labels, and broken ARIA. Start here to find the obvious issues.

Use Foglift's free accessibility checker to scan any URL instantly. It checks for WCAG 2.2 violations and provides specific fix recommendations alongside your SEO, performance, and security scores.

Step 2: Keyboard-Only Navigation Test

Unplug your mouse (or on a laptop, don't touch the trackpad) and navigate your entire site using only the keyboard:

• Tab to move between interactive elements
• Shift+Tab to move backward
• Enter to activate links and buttons
• Space to toggle checkboxes and activate buttons
• Escape to close modals and dropdowns
• Arrow keys to navigate within menus, tabs, and radio groups

If you get stuck (focus trapped in an element) or can't reach something, that's a WCAG failure.

Step 3: Screen Reader Testing

Test with at least one screen reader. Free options are built into every operating system:

• VoiceOver (macOS/iOS) — press Cmd+F5 to activate
• NVDA (Windows) — free, open-source download
• TalkBack (Android) — built into Android settings

Navigate your key user flows: landing page, signup, checkout. Listen for confusing announcements, missing labels, and illogical reading order.

Step 4: Zoom and Reflow Testing

Zoom your browser to 200% (Ctrl/Cmd + several times). WCAG requires that content remains usable at 200% zoom without horizontal scrolling for vertical-scrolling pages. Check that text reflows properly, nothing overlaps, and all functionality is still accessible.

Free Accessibility Checker Tools: Comparison

Here is how the most popular free web accessibility testing tools compare:

Recommendation: Start with Foglift for a quick scan that also covers SEO and performance. Then use axe DevTools or WAVE for deeper page-level inspection during development.

The SEO and Accessibility Overlap

Accessibility and SEO share more DNA than most people realize. Many WCAG requirements directly improve search rankings, and vice versa. Here is where they intersect:

• Alt text: Screen readers need it for images. Google uses it to understand image content and serve Google Image results.
• Heading hierarchy: Assistive technology uses headings for page navigation. Search engine crawlers use headings to understand content structure and topic hierarchy.
• Semantic HTML: Native elements like <nav>, <main>, <article> help both screen readers and crawlers understand page layout.
• Page titles and meta descriptions: WCAG requires descriptive page titles. Search engines use them as the primary ranking signal for page relevance.
• Link text: "Click here" links fail both WCAG (screen reader context) and SEO (anchor text signals). Descriptive link text serves both.
• Site speed: Fast-loading pages are more accessible (users on assistive technology often experience magnified delays) and rank better in Core Web Vitals assessments.
• Mobile responsiveness: Content that reflows properly helps both users who zoom and mobile search rankings.

Running a combined free website audit that checks both accessibility and SEO is the most efficient way to catch issues that affect both user experience and search visibility.

Building an Accessibility Testing Workflow

One-time audits are not enough. Accessibility issues creep back in with every new feature, content update, and design change. Here is a practical workflow:

During Development

• Use axe DevTools or the browser accessibility inspector while building features
• Write semantic HTML first; add ARIA only when native elements are insufficient
• Test keyboard navigation as you build interactive components

Pre-Deployment

• Run Pa11y or axe-core in your CI/CD pipeline to catch regressions
• Set a policy: no deployment if new critical a11y issues are introduced

Post-Launch Monitoring

• Run periodic automated scans on key pages
• Conduct quarterly manual audits with keyboard and screen reader testing
• Track your accessibility score over time alongside your technical SEO metrics

Frequently Asked Questions