Web accessibility is no longer optional. With new ADA Title II regulations expanding to cover state and local government websites, and private businesses increasingly targeted by litigation, the question is no longer whether to test your site for accessibility — it's how.
This guide covers everything you need to know about WCAG 2.1 accessibility checkers: what they test, how to interpret results, and how to fix what they find. We'll also show you how to run a free website accessibility test in under 60 seconds.
See how 321 websites scored →
View the 2026 ReportWCAG stands for Web Content Accessibility Guidelines. Version 2.1, published by the W3C in 2018, is the current global standard for web accessibility. It's organized around four core principles, often remembered by the acronym POUR:
Each principle contains success criteria rated at three conformance levels: A (minimum), AA (industry standard), and AAA (enhanced). WCAG 2.1 Level AA is what most regulations and lawsuits reference. This is the bar your website should meet.
Automated accessibility scanners can catch a significant portion of WCAG 2.1 violations instantly. Here's what a good WCAG scanner checks:
Text must have a contrast ratio of at least 4.5:1 against its background (3:1 for large text). Low contrast is the most common accessibility failure we see — present on over 80% of sites we scan. That light gray text on white background your designer loves? It's likely failing.
Every meaningful image needs a descriptive alt attribute. Decorative images should have alt="" so screen readers skip them. Missing or generic alt text ("image.jpg", "photo") fails this criterion.
All interactive elements — links, buttons, form fields, dropdowns — must be reachable and operable by keyboard alone. This ensures usability for people who can't use a mouse. A good scanner checks focus order, visible focus indicators, and keyboard traps.
Every form input needs a programmatically associated label. Placeholder text doesn't count — it disappears when users start typing and isn't always read by screen readers.
ARIA (Accessible Rich Internet Applications) attributes add semantic meaning to dynamic content. But bad ARIA is worse than no ARIA — incorrect roles or missing required attributes create confusion for assistive technologies.
Page headings (h1–h6) should form a logical outline. Skipping from an h1 to an h4, or using headings purely for visual styling, breaks navigation for screen reader users.
Links labeled "click here" or "read more" are meaningless out of context. Screen reader users often navigate by scanning a list of all links on the page — descriptive link text is essential.
The fastest way is Accessalyze. Paste any public URL, and you'll get a full WCAG 2.1 AA report in seconds — no account, no credit card, no waiting.
Scan any public website instantly. Get a full report with violations, severity levels, and fix guidance.
🔍 Scan My Website Free →After you paste your URL, the scanner checks:
Results are categorized by severity (critical, serious, moderate, minor) and include the exact HTML element that failed, the WCAG criterion it violates, and — in Pro mode — generated fix code.
Once your scan completes, you'll see a breakdown like this:
| Severity | What It Means | Priority |
|---|---|---|
| Critical | Blocks users with disabilities entirely | Fix immediately |
| Serious | Significantly impairs usability | Fix this sprint |
| Moderate | Creates friction but workarounds exist | Schedule for next release |
| Minor | Best practice violations | Fix when convenient |
Start with critical and serious issues. These are the failures most likely to block users who rely on assistive technology — and they're typically the ones that show up in ADA demand letters.
After scanning 300+ websites — from small businesses to government agencies — here's what actually fails most often:
The good news: fixing the top two or three issues on this list will eliminate the majority of barriers for most users with disabilities — and reduce your legal exposure significantly.
Most free WCAG scanners give you a violation count and element references. That's useful for triage. Paid tools typically add:
For most small business owners, a free scan is the right starting point. It tells you where you stand, which is the information you need before deciding how much remediation effort is required.
WCAG 2.2, published in October 2023, added nine new success criteria, including improved focus appearance requirements and new criteria for dragging movements. However:
Our recommendation: test against WCAG 2.1 AA as your baseline. Meeting that standard keeps you in compliance with current regulations. WCAG 2.2 compliance is a forward-looking investment that future-proofs your site.
Accessibility failures are not just a user experience problem — they're a legal one. ADA Title III applies to websites serving the public. In 2024, over 4,000 ADA web accessibility lawsuits were filed in federal court, and that number is rising. Most start with automated scanning by plaintiff law firms.
The remediation path is straightforward:
Most sites can eliminate their highest-risk violations in a focused one-week sprint.
Accessalyze scans any public URL against the full WCAG 2.1 AA standard. The free tier covers single-page scans with full violation details. No account required.
If you want to understand more about what we built and why, read how an AI company built this accessibility scanner in 14 days →
Free · No signup · Instant WCAG 2.1 AA results · 300+ sites already scanned
🔍 Scan My Website Free →50+ checkpoints with how-to-fix guidance for every criterion. Print it. Use it at your next audit.
Get Free Checklist →Related reading: Automated vs Manual Accessibility Testing · How to Fix WCAG Color Contrast Errors · Free WCAG 2.1 AA Compliance Checklist · Accessalyze vs Axe
Try it yourself
Enter your website URL to get a free accessibility score.