Free WCAG 2.1 AA Compliance Checker
The Web Content Accessibility Guidelines (WCAG) are the international standard for web accessibility. AccessScore checks your website against WCAG 2.1 Level A and AA criteria — the conformance levels referenced in ADA lawsuits, Section 508, and the EU European Accessibility Act. Scan any URL for free, get your score (0-100), and receive fix code for every violation detected.
50+ automated checks. Fix code included. No signup.
Understanding WCAG Conformance Levels
Essential accessibility (minimum)
The minimum level of conformance. Failure means some users literally cannot access your content. Includes requirements like alt text for images, keyboard navigation, and page titles. WCAG 2.1 Level A has 30 success criteria.
Standard compliance target (what laws require)
The level required by virtually all accessibility laws and regulations worldwide. Includes color contrast ratios (4.5:1 for text), text resizing to 200%, consistent navigation, and error identification. WCAG 2.1 Level AA adds 20 success criteria beyond Level A. This is what courts reference in ADA cases.
Enhanced accessibility (aspirational)
The highest level of conformance. Not typically required by law, but recommended for specialized content serving users with cognitive or learning disabilities. Includes sign language for video, extended audio descriptions, and simplified language. WCAG 2.1 Level AAA adds 28 more criteria.
WCAG Versions: 2.0 vs 2.1 vs 2.2
WCAG has evolved through three major versions. Understanding the differences helps you target the right standard for your compliance needs.
| Version | Year | Total Criteria | Key Additions | Legal Status |
|---|---|---|---|---|
| WCAG 2.0 | 2008 | 61 | Foundational web accessibility criteria | Outdated |
| WCAG 2.1 | 2018 | 78 | Mobile, cognitive, low vision | Current standard |
| WCAG 2.2 | 2023 | 87 | Focus appearance, dragging, help | Emerging |
WCAG 2.1 Level AA is the current legal standard in most jurisdictions. Each version is backward-compatible — if you comply with WCAG 2.1, you also comply with WCAG 2.0. AccessScore checks against WCAG 2.1 AA criteria, which provides the broadest legal coverage.
WCAG 2.1 Success Criteria We Check
WCAG 2.1 contains 78 success criteria across four principles (POUR): Perceivable, Operable, Understandable, and Robust. AccessScore checks the most impactful criteria using both the axe-core engine and custom accessibility checks.
Perceivable (Information users can see, hear, or touch)
SC 1.1.1: Non-text Content
All images, icons, and non-text elements must have text alternatives (alt text) that serve an equivalent purpose.
SC 1.2.2: Captions (Prerecorded)
Prerecorded audio content in synchronized media (video) must have captions.
SC 1.3.1: Info and Relationships
Semantic structure — headings, landmarks, lists, tables, form labels — must be programmatically determinable.
SC 1.4.2: Audio Control
Audio that plays automatically for more than 3 seconds must have a pause/stop mechanism or volume control.
SC 1.4.3: Contrast (Minimum)
Text must have a contrast ratio of at least 4.5:1 (3:1 for large text 18pt+ or 14pt bold).
SC 1.4.4: Resize Text
Text must be resizable up to 200% without loss of content or functionality.
SC 1.4.10: Reflow
Content must reflow without horizontal scrolling at 320 CSS pixels width (400% zoom).
Operable (Users can navigate and interact)
SC 2.1.1: Keyboard
All functionality must be operable through a keyboard interface (no mouse-only interactions).
SC 2.4.1: Bypass Blocks
A mechanism (skip navigation link) must allow users to bypass repeated content blocks.
SC 2.4.2: Page Titled
Web pages must have descriptive, unique titles that identify their topic or purpose.
SC 2.4.3: Focus Order
Focusable components must receive focus in an order that preserves meaning and operability.
SC 2.4.4: Link Purpose (In Context)
The purpose of each link must be determinable from the link text alone or from its context.
SC 2.4.7: Focus Visible
Any keyboard-operable interface must have a visible keyboard focus indicator.
Understandable (Users can comprehend the content)
SC 3.1.1: Language of Page
The default human language of each page must be programmatically determinable (lang attribute on <html>).
SC 3.3.1: Error Identification
If an input error is automatically detected, the item in error must be identified and described in text.
SC 3.3.2: Labels or Instructions
Labels or instructions must be provided when content requires user input.
Robust (Content works with assistive technologies)
SC 4.1.1: Parsing
HTML must be well-formed with complete start/end tags, proper nesting, no duplicate attributes, and unique IDs.
SC 4.1.2: Name, Role, Value
All UI components must have programmatically determinable names, roles, and states (proper ARIA usage).
Why WCAG Compliance Matters for Your Business
WCAG compliance is not just a technical standard — it has direct legal and business implications:
Legal Requirements by Jurisdiction
United States (ADA)
Courts reference WCAG 2.1 AA in Title III cases. DOJ's April 2024 rule explicitly requires WCAG 2.1 AA for government sites (Title II). Over 4,000 lawsuits filed in 2024.
European Union (EAA)
European Accessibility Act (effective June 2025) requires WCAG 2.1 AA for websites and mobile apps of businesses selling to EU consumers. EN 301 549 is the technical standard.
Canada (AODA)
Accessibility for Ontarians with Disabilities Act requires WCAG 2.0 AA. Federal Accessible Canada Act extends requirements nationally.
United Kingdom (Equality Act)
Public sector must meet WCAG 2.1 AA. Private sector has duty to make reasonable adjustments under the Equality Act 2010.
Australia (DDA)
Disability Discrimination Act 1992 covers websites. WCAG 2.0 AA is the referenced standard.
Business Benefits Beyond Legal Compliance
- SEO improvement — Many WCAG criteria (alt text, heading structure, page titles, semantic HTML) directly improve search engine optimization. Google uses Core Web Vitals, which overlap with accessibility metrics.
- Larger audience — 15-20% of the global population has a disability. Inaccessible websites exclude potential customers.
- Better user experience — Accessible websites are easier to use for everyone, including users on mobile devices, older adults, and users in challenging environments.
- Brand reputation — Demonstrating commitment to accessibility builds trust and avoids the negative publicity of an ADA lawsuit.
Limitations of Automated WCAG Checking
Automated WCAG checkers like AccessScore can identify approximately 30-57% of WCAG violations. Some criteria require human judgment that cannot be automated:
Automated checks can detect:
- • Missing alt text on images
- • Insufficient color contrast
- • Missing form labels
- • Broken heading hierarchy
- • Missing page language
- • Duplicate IDs
- • Missing skip navigation
- • Invalid ARIA attributes
Manual testing required for:
- • Whether alt text is actually descriptive
- • Logical reading order
- • Complex keyboard interactions
- • Cognitive accessibility
- • Video caption accuracy
- • Custom widget operability
- • Timeout handling
- • Error recovery guidance
For complete WCAG compliance, supplement automated scanning with manual testing using screen readers (NVDA, JAWS, VoiceOver), keyboard-only navigation, and user testing with people who have disabilities. Our accessibility audit guide explains the complete process, and our accessibility checklist provides a comprehensive list of items to verify manually.
How to Run a WCAG 2.1 AA Check
Enter your URL on the AccessScore homepage
Paste any publicly accessible URL. The tool works with any website regardless of platform — WordPress, Shopify, React, static HTML, or any other technology.
Review your score and violations
AccessScore assigns a score from 0-100 and a letter grade (A-F). Each violation lists the specific WCAG success criterion it fails, the affected element, and the fix code.
Fix violations in priority order
Start with critical violations (Level A failures) before addressing Level AA issues. The fix code provided is copy-paste ready.
Re-scan after fixes
Run the checker again to verify your fixes resolved the violations. Repeat until you reach a satisfactory score.
For developers, AccessScore also provides a CLI tool via npm (npx accessscore https://your-site.com) and a GitHub Action for CI/CD integration. Both are completely free with no usage limits.
WCAG Checker FAQ
What is the difference between WCAG 2.0, 2.1, and 2.2?
WCAG 2.0 (2008) established 61 success criteria. WCAG 2.1 (2018) added 17 new criteria focused on mobile accessibility, cognitive disabilities, and low vision — totaling 78 criteria. WCAG 2.2 (2023) added 9 more criteria including focus appearance, dragging movements, and consistent help. Each version is backward-compatible. Courts in the US primarily reference WCAG 2.1 Level AA.
Which WCAG level do I need to comply with?
For most legal and regulatory requirements, WCAG 2.1 Level AA is the target. This is referenced in US ADA lawsuits, the EU European Accessibility Act, Canada's AODA, and the UK's Equality Act. Level A is the minimum, Level AA is what laws require, and Level AAA is aspirational.
Can automated tools check all WCAG criteria?
No. Automated tools check approximately 30-57% of WCAG criteria. Many criteria require human judgment. AccessScore maximizes automated coverage using dual scanning engines (axe-core + custom checks) and clearly indicates which issues require manual review. For a complete audit approach, see our accessibility audit guide.
How long does it take to achieve WCAG 2.1 AA compliance?
It depends on your site's size and complexity. A simple site (5-10 pages) can typically be fixed in 1-2 weeks. Medium e-commerce sites (50-200 pages) usually take 4-8 weeks. Large enterprise sites may require 3-6 months. Start by running the WCAG checker to understand your current state, then use our fix guide to prioritize remediation.
Check Your WCAG Compliance Now
Find out how your website scores against WCAG 2.1 AA criteria. Get fix code for every violation.
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