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Free Website
Accessibility Checker

Enter any URL and get an instant WCAG 2.1 compliance score. Check your website accessibility online, see the critical issues that put you at legal risk, and get AI-powered fix suggestions — all in under 60 seconds.

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No signup required. Scans your homepage for free.

WCAG 2.1 AA Testing ADA Compliance Section 508 EAA Ready AI-Powered Fixes

How the Free Accessibility Check Works

Step 1

Enter Your URL

Type any website address. We scan the homepage using the same axe-core engine used by Microsoft, Google, and Deque Systems.

Step 2

Get Instant Results

Within 60 seconds, see your WCAG compliance score. The free scan includes your score and 2 sample issues.

Step 3

Unlock Full Report

Sign up free to unlock all issues, severity breakdown, AI-powered code fixes, element screenshots, multi-page scanning, and more.

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Free forever — no credit card required

What Our Accessibility Scanner Checks

Powered by axe-core and enhanced with AI, our scanner tests 50+ accessibility criteria across all four WCAG 2.1 principles.

Perceivable

  • Image alt text
  • Color contrast ratios
  • Text alternatives
  • Captions & audio descriptions

Operable

  • Keyboard navigation
  • Focus management
  • Skip navigation links
  • Timing & motion control

Understandable

  • Form labels & instructions
  • Error identification
  • Language attributes
  • Consistent navigation

Robust

  • Valid ARIA attributes
  • Semantic HTML structure
  • Markup validation
  • Screen reader compatibility

Also check if AI agents can discover your site → Free Agent Readiness Check

The Issues This Accessibility Checker Finds Most Often

The WebAIM Million study found detectable WCAG failures on 96.3% of the top one million home pages. Certvo's own scan of 1,564 business websites agrees: only 18.8% passed every automated AA check, and 62.4% had content placed outside any landmark region. These six issues account for the large majority of failures, and every one has a documented fix guide on Certvo.

Low colour contrast

WCAG 1.4.3~81% of sites

Body text below the 4.5:1 contrast ratio (3:1 for large text). Usually a single design-token change fixes it site-wide.

How to fix low colour contrast →

Missing image alt text

WCAG 1.1.1~55% of sites

Informative images with no text alternative, and decorative images that fail to use an empty alt attribute.

How to fix missing image alt text →

Empty or ambiguous links

WCAG 2.4.4~48% of sites

Icon-only links with no accessible name, plus repeated “click here” and “read more” labels that mean nothing out of context.

How to fix empty or ambiguous links →

Form inputs without labels

WCAG 3.3.2~44% of sites

Inputs relying on placeholder text alone. Screen readers announce the field as unlabelled once typing starts.

How to fix form inputs without labels →

Missing or skipped headings

WCAG 1.3.1~38% of sites

A page with no h1 at all, styled divs used as headings, or jumps from h2 straight to h4 — all of which break screen-reader navigation.

How to fix missing or skipped headings →

Missing document language

WCAG 3.1.1~17% of sites

No lang attribute on the html element, so screen readers guess the pronunciation of every word on the page.

How to fix missing document language →

See every issue type in the accessibility fix library, or browse the WCAG 2.1 success criteria reference.

What an Automated Accessibility Check Can and Cannot Tell You

No automated website accessibility checker — ours included — catches 100% of WCAG failures. Roughly 30–40% of success criteria are machine-testable. Here is the honest split.

What automated accessibility testing detects and what needs a humanTwo columns. Automated testing reliably detects contrast ratios, missing alt attributes, unlabelled form controls, invalid ARIA roles and states, heading order and landmarks, and document language and page title — roughly 30 to 40 percent of WCAG success criteria. A human reviewer is still needed to judge whether alt text is meaningful, whether reading order makes sense, whether focus order matches the visual layout, whether error messages help, whether captions are accurate, and what the real screen-reader experience is like.Detected automatically~30–40% of WCAG success criteriaNeeds a human reviewerJudgement, not detectionContrast ratiosMissing alt attributesUnlabelled form controlsInvalid ARIA roles and statesHeading order and landmarksDocument language and page titleWhether alt text is meaningfulWhether reading order makes senseWhether focus order matches layoutWhether error messages helpWhether captions are accurateReal screen-reader experience
Six machine-decidable checks against six that need judgement. No scanner — ours included — covers the right-hand column.

Detected automatically

  • Contrast ratios of text against its computed background
  • Missing alt attributes, empty links and buttons
  • Form controls with no programmatic label
  • Invalid ARIA roles, states and properties
  • Heading order, landmark structure, duplicate IDs
  • Missing document language and page title
  • Auto-playing media and missing captions tracks

Needs a human reviewer

  • Whether alt text actually describes the image
  • Whether the reading order makes sense
  • Whether focus order follows the visual layout
  • Whether error messages are genuinely helpful
  • Whether captions are accurate and synchronised
  • Whether a custom widget behaves as its role implies
  • Screen-reader experience on real assistive technology

This is why Certvo pairs the automated scan with AI-generated code fixes and a manual testing checklist: the scan narrows a thousand-page site down to the handful of places a person actually needs to look.

Free Scan vs Full Account

Get started with a free scan, then unlock everything with a free account.

Feature
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Free Account
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Pro Plan
Starting at $29/mo
Overall accessibility score
Sample issues (2)
All issues with details
Severity breakdown
AI-powered code fixes
Element screenshots
Multi-page scanning
Recurring monitoring
Compliance certificates
White-label reports
Team collaboration
API access
Create Free Account See All Plans

How Certvo Compares to Other Free Accessibility Checkers

Most free tools stop at a list of violations. The gap between “here are your problems” and “here is the code that fixes them” is where remediation time actually goes.

Fixes, not just findings

Every issue comes with generated, copy-paste code written against your actual markup — not a generic WCAG quotation.

Mapped to the law, not just the standard

Each finding is tied to its WCAG success criterion and to the ADA, Section 508 and European Accessibility Act obligations it affects.

Monitoring, not one-off audits

Scheduled rescans catch regressions introduced by a theme update or a new landing page, before an auditor or a plaintiff does.

Built for AI workflows

An MCP server plugs Certvo straight into Claude, Cursor and other agents, so fixes can be applied where the code already lives.

Weighing specific tools? Read the side-by-side comparisons of Certvo against the widgets and scanners you are probably also considering.

Why Check Your Website's Accessibility?

Legal Compliance

The ADA, Section 508, and European Accessibility Act (effective June 2025) require WCAG compliance. Non-compliance risks lawsuits costing $50,000–$150,000 and fines.

Better SEO Rankings

Accessibility best practices — semantic HTML, alt text, heading structure, keyboard navigation — directly improve search engine rankings and Core Web Vitals scores.

Reach 1.3 Billion Users

Over 16% of the world population lives with a disability. An accessible website opens your business to a $13 trillion annual market.

Reduce Legal Risk

Web accessibility lawsuits increased 320% since 2018. Over 4,600 cases were filed in 2023 alone. A proactive approach costs far less than litigation.

Accessibility isn't just about humans. AI agents also need to discover and interact with your site. Check your AI agent readiness →

Web Accessibility by the Numbers

18.8%

of 1,564 websites passed every automated AA check

Certvo Web Accessibility Report 2026

65.9

average accessibility score out of 100

Certvo Web Accessibility Report 2026

51.5%

of websites had at least one critical issue

Certvo Web Accessibility Report 2026

96.3%

of top 1M home pages have detectable WCAG failures

WebAIM Million 2024

Source: Certvo Web Accessibility Report 2026, automated scan of 1,564 websites (2026-03-16 to 2026-09-06). Read the full report

Ready for a Full Accessibility Audit?

Sign up free and get your complete report — all issues, severity breakdown, AI-powered code fixes, element screenshots, and a WCAG compliance score.

Create Free AccountView Plans

No credit card required. Takes 30 seconds to sign up.

Frequently Asked Questions

What does this accessibility checker test?

Our scanner checks your website against WCAG 2.1 Level AA guidelines using axe-core engine and AI analysis. It tests for color contrast, missing alt text, heading hierarchy, ARIA attributes, keyboard navigation, form labels, and 50+ other accessibility criteria.

Is this really free? What are the limits?

Yes! The free scan checks your homepage and shows your overall score plus 2 sample issues. To unlock the full report — including all issues across multiple pages, severity breakdown, AI-powered code fix suggestions, and compliance reports — you need a free account.

How accurate is the scanner?

We use axe-core (the same engine used by Microsoft, Google, and Deque) combined with Chrome headless rendering and AI analysis. This catches both automated detectable issues and many semi-automated issues.

Can an automated checker find every accessibility problem?

No, and any tool that claims otherwise is overselling. Automated testing reliably covers roughly 30–40% of WCAG success criteria — the machine-testable ones such as contrast ratios, missing alternative text, unlabelled form controls and invalid ARIA. Judgement calls like whether alt text is meaningful, whether focus order matches the visual layout, or whether an error message is actually helpful still need a human reviewer.

What is WCAG 2.1 AA?

WCAG 2.1 Level AA is the internationally recognized standard for web accessibility. It covers four principles: Perceivable, Operable, Understandable, and Robust. Most legal frameworks (ADA, Section 508, EAA) reference WCAG 2.1 AA as the compliance target.

How is the accessibility score calculated?

The score is calculated on a 0-100 scale based on the number and severity of WCAG violations found. Critical and serious issues have a larger impact than moderate or minor ones. A score of 90+ indicates excellent accessibility.

Does my site need to be accessible?

Yes. Legal requirements like the ADA (US), Section 508 (US government), and the European Accessibility Act (EU, effective June 2025) require digital accessibility. Non-compliance can result in lawsuits and fines. Beyond legal risk, accessible sites reach 16% more users.

What happens after the free scan?

After the free scan, you can sign up (free) to unlock the full report with all issues, AI-powered code fixes, element screenshots, multi-page scanning, recurring monitoring, and downloadable compliance certificates.

How often should I check my website?

Accessibility should be checked after every major content or design update. For ongoing compliance, we recommend weekly automated scans with certvo.com monitoring — available with a free account.

Can certvo.com fix accessibility issues automatically?

Yes. Our AI engine generates copy-paste code fixes for each issue — covering alt text, ARIA labels, color contrast, heading structure, and more. You also get before/after screenshots and WCAG reference links.

What is the European Accessibility Act (EAA)?

The European Accessibility Act (EAA) takes effect on June 28, 2025. It requires digital products and services in the EU to meet accessibility standards. Businesses must comply or face significant fines. certvo.com helps you prepare.

Explore More Accessibility Resources

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WCAG 2.1 Guide

Complete guide to web accessibility standards and levels

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Accessibility Blog

Latest articles on WCAG, ADA, EAA, and accessibility best practices