What Is WCAG and Why Does Compliance Matter?
The Web Content Accessibility Guidelines (WCAG) are the global standard for web accessibility. Published by the W3C's Web Accessibility Initiative, WCAG defines how to make web content accessible to people with disabilities — including visual, auditory, physical, speech, cognitive, and neurological disabilities.
WCAG compliance matters because:
- It's legally required — The DOJ has formally recognized WCAG 2.1 AA as the standard for ADA compliance. The ADA Title II rule (effective April 2026) explicitly mandates WCAG 2.1 AA for government websites.
- Lawsuits are surging — Over 4,600 web accessibility lawsuits were filed in 2025 alone. Plaintiff firms specifically target sites with WCAG violations.
- It's good business — 1.3 billion people worldwide live with disabilities. An inaccessible website excludes 15-20% of potential customers.
- It improves SEO — Many WCAG requirements (alt text, semantic HTML, heading structure) directly improve search engine rankings.
How Our WCAG Compliance Tool Works
Enter any URL
Paste the web address you want to test. Our tool works with any publicly accessible webpage.
Real browser analysis
We load your page in a real Playwright browser instance — not just the HTML source. This catches JavaScript-rendered content, dynamic widgets, and single-page applications that simpler crawlers miss.
axe-core engine testing
We run the industry-standard axe-core accessibility engine against the fully-rendered page. This is the same engine used by Microsoft, Google, and Deque for accessibility testing.
WCAG-mapped results
Every violation is mapped to its specific WCAG success criterion (e.g., 1.4.3 Contrast Minimum). You know exactly which standard you're failing and why.
Actionable fix instructions
Each issue includes a plain-language description, the affected HTML elements, and specific instructions for fixing the problem.
WCAG 2.1 AA Criteria We Test
Our tool tests against all four WCAG principles — the foundation of web accessibility. Here's what each principle covers and the specific criteria we check:
Perceivable
Content must be presentable to users in ways they can perceive
- 1.1.1 Non-text Content — All images, icons, and media have text alternatives
- 1.3.1 Info and Relationships — Semantic HTML conveys structure and relationships
- 1.4.1 Use of Color — Color isn't the only way to convey information
- 1.4.3 Contrast (Minimum) — Text has 4.5:1 contrast ratio against backgrounds
- 1.4.10 Reflow — Content reflows at 320px without horizontal scrolling
Operable
Users must be able to operate the interface
- 2.1.1 Keyboard — All functionality available via keyboard
- 2.1.2 No Keyboard Trap — Focus can always be moved away from any element
- 2.4.1 Bypass Blocks — Skip navigation links to bypass repeated content
- 2.4.3 Focus Order — Focusable elements receive focus in a logical order
- 2.4.7 Focus Visible — Keyboard focus indicator is always visible
Understandable
Content and interface must be understandable
- 3.1.1 Language of Page — Default language is programmatically set
- 3.2.1 On Focus — No unexpected context changes on focus
- 3.3.1 Error Identification — Input errors are automatically detected and described
- 3.3.2 Labels or Instructions — Form inputs have clear labels
- 3.3.3 Error Suggestion — Fix suggestions are provided for input errors
Robust
Content must be robust enough for diverse user agents
- 4.1.1 Parsing — HTML is well-formed with no duplicate IDs
- 4.1.2 Name, Role, Value — Custom components expose proper ARIA attributes
- 4.1.3 Status Messages — Status updates are announced to screen readers
Understanding WCAG Conformance Levels
| Level | Requirements | Who Needs It |
|---|---|---|
| Level A | Basic accessibility — bare minimum to function. 30 success criteria. | Everyone — these are non-negotiable |
| Level AA ⭐ | Standard accessibility — addresses major barriers. 20 additional criteria. | Required by ADA, Section 508, EAA, and most laws worldwide |
| Level AAA | Enhanced accessibility — highest standard. 28 additional criteria. | Specialized audiences (government, healthcare, education) |
Level AA is the legal standard. When the DOJ, courts, or regulators reference "WCAG compliance," they mean Level AA. This is what our tool tests against, and it's the level you should target for ADA compliance.
How RatedWithAI Compares to Other WCAG Tools
| Feature | RatedWithAI | WAVE | Lighthouse | Pa11y |
|---|---|---|---|---|
| Free tier | ✓ Unlimited | ✓ Extension | ✓ Built-in | ✓ Open source |
| No install required | ✓ | Extension needed | DevTools needed | CLI install |
| WCAG criteria mapping | ✓ Per violation | ✓ | Limited | ✓ |
| Compliance scoring | ✓ 0-100 score | ✗ | ✓ 0-100 | ✗ |
| Plain-language fixes | ✓ | Technical only | Technical only | Technical only |
| Continuous monitoring | ✓ Pro plan | ✗ | ✗ | DIY setup |
| Non-technical friendly | ✓ | Moderate | ✗ | ✗ |
Most Common WCAG Violations Found
Based on scanning thousands of websites, these are the WCAG failures we find most often:
Low contrast text (WCAG 1.4.3)
Text doesn't meet the 4.5:1 contrast ratio against its background color.
Missing alt text (WCAG 1.1.1)
Images without text alternatives, making them invisible to screen readers.
Missing form labels (WCAG 3.3.2)
Form inputs without associated labels, so users don't know what to enter.
Empty links (WCAG 2.4.4)
Links with no discernible text — screen readers announce 'link' with no context.
Missing page language (WCAG 3.1.1)
No lang attribute on HTML, preventing screen readers from selecting the right language.
Frequently Asked Questions
Is this WCAG compliance tool really free?
Yes. You can scan any URL for WCAG 2.1 AA violations as many times as you want with no signup and no credit card. Our free scanner uses the same axe-core engine as our paid monitoring plans.
Which version of WCAG does this tool test?
We test against WCAG 2.1 Level AA — the version formally adopted by the DOJ for ADA compliance, referenced by Section 508, and required by the European Accessibility Act. This is the globally accepted standard for web accessibility.
Can automated tools guarantee WCAG compliance?
No automated tool can test 100% of WCAG criteria — some require human judgment (like whether alt text is meaningful, or if content order makes sense). Automated tools typically catch 30-40% of issues, but these are the most common and legally actionable violations. We recommend combining automated scanning with periodic manual review.
What's the difference between WCAG 2.0, 2.1, and 2.2?
WCAG 2.1 (2018) adds 17 criteria to WCAG 2.0, focused on mobile accessibility, low vision, and cognitive disabilities. WCAG 2.2 (2023) adds 9 more criteria. The DOJ's ADA Title II rule requires 2.1 AA, which is what most organizations should target. Our tool tests 2.1 AA criteria. Read our full WCAG version comparison →
How often should I test for WCAG compliance?
At minimum, test after every major code deployment and quarterly for regression checks. Ideally, set up continuous monitoring that scans automatically on a schedule. Our Pro plan includes automated monitoring with email alerts when new violations are detected.
Does passing a WCAG scan mean I'm ADA compliant?
Passing an automated WCAG scan is a strong indicator but not a legal guarantee. Full ADA compliance also requires addressing issues that automated tools can't detect (manual testing) and maintaining ongoing compliance as content changes. However, automated scanning catches the violations most commonly cited in accessibility lawsuits.
Test Your Website's WCAG Compliance Now
Paste any URL and get a detailed WCAG 2.1 AA compliance report in under 60 seconds. Free, instant, no signup.
Run Free WCAG Compliance Test →Need continuous monitoring? See our Pro plans starting at $29/mo.