Website Accessibility and A11y Checklist
Accessibility is not a compliance checkbox. It is how search engines already read your page. Screen readers and Googlebot both parse the same HTML source, which is why semantic HTML, descriptive alt text, and proper headings serve both audiences. The WebAIM Million study found 96.3% of the top one million homepages had detectable WCAG failures, most commonly low-contrast text. This checklist walks through WCAG 2.2 AA so your site is usable, compliant, and easier to understand.
Accessibility Is Good SEO
Around 1 in 4 adults in the United States lives with a disability, and courts continue to apply Title III of the ADA to websites. WCAG 2.2 AA has become the accepted technical standard for demonstrating compliance. Every accessibility fix also helps you rank: headings give structure, alt text gives context to images, and semantic HTML tells crawlers what each element means.
The overlap is real. A page that is keyboard-navigable is a page crawlers can traverse. Descriptive anchor text is both an accessibility requirement and a ranking signal. Image alt text is both a WCAG success criterion and an image SEO signal. Fixing one improves the other, which makes website accessibility and WCAG compliance one of the cheapest technical SEO wins available. This page is part of the complete technical SEO checklist.
The pattern of using a single div for a button, adding a click handler, and then sprinkling ARIA to fake a button is everywhere, and it fails users and search engines equally. Native HTML wins every time. Start with the source, not with ARIA.
Sources
- 96.3% of the top 1,000,000 homepages had detectable WCAG failures in 2024, WebAIM Million 2024.
- Low-contrast text was the most common accessibility failure on homepages, WebAIM Million 2024.
WCAG Conformance Levels
The 15 Accessibility Checks
Audit your source code against WCAG 2.2 AA requirements.
| # | Check | Who Does It | Tool | Difficulty |
|---|---|---|---|---|
| 1 | Use semantic HTML5 landmarks and native elements | Developer | HTML / validator | Easy |
| 2 | Write descriptive alt text for meaningful images | You | CMS / audit | Easy |
| 3 | Maintain a logical heading hierarchy | You | Audit | Easy |
| 4 | Add a skip link that bypasses navigation | Developer | HTML | Easy |
| 5 | Ensure full keyboard navigation | Developer | Manual test | Medium |
| 6 | Provide visible focus indicators | Developer | CSS | Easy |
| 7 | Meet 4.5:1 text and 3:1 UI contrast | You | Contrast checker | Easy |
| 8 | Use ARIA only when native HTML is insufficient | Developer | Code review | Medium |
| 9 | Label every form field and input | Developer | HTML | Easy |
| 10 | Write descriptive, context-aware link text | You | Audit | Easy |
| 11 | Caption and transcribe media | You | Media tools | Medium |
| 12 | Respect reduced motion preferences | Developer | CSS / JS | Medium |
| 13 | Provide adequate touch target sizes | Developer | CSS | Easy |
| 14 | Keep focus order in the visual order | Developer | Manual test | Medium |
| 15 | Run automated checks and screen reader tests | You | axe / Lighthouse | Medium |
Deep Dive: Every Check Explained
How to meet each WCAG 2.2 AA success criterion.
1 Use Semantic HTML5 Landmarks and Native Elements
Use header, nav, main, aside, footer, article, section, and native button and a elements. Screen readers announce landmarks for navigation, and search engines use them to understand page structure. A site made of generic divs is invisible to assistive technology until you manually bolt on ARIA roles.
2 Write Descriptive Alt Text for Meaningful Images
Every meaningful image needs concise alt text describing its purpose, ideally under 125 characters. Decorative images use empty alt. Alt text is simultaneously a WCAG success criterion and an image SEO signal. Do not repeat the image caption or stuff keywords.
3 Maintain a Logical Heading Hierarchy
One H1 per page and a clean H2 to H3 progression with no skipped levels. Headings are navigation for screen reader users and the backbone of on-page SEO. A heading tree that jumps from H2 to H4 confuses both.
4 Add a Skip Link That Bypasses Navigation
WCAG requires a way to bypass repeated blocks. A skip link at the top of the page that jumps to the main content is the standard solution. It must be visible when it receives keyboard focus, not hidden until hover.
5 Ensure Full Keyboard Navigation
Every interactive element must be reachable and operable with the Tab key alone. Remove tabindex values above zero, provide keyboard handlers for custom widgets, and make sure nothing traps focus. Keyboard traversal mirrors how crawlers move through the DOM.
6 Provide Visible Focus Indicators
Focus must be visually apparent at all times, with WCAG 2.2 tightening the minimum focus appearance requirement. Do not hide outlines or replace them with invisible styling. A strong focus ring is also a usability win for mouse users who tab.
7 Meet 4.5:1 Text and 3:1 UI Contrast
Normal text needs a 4.5:1 contrast ratio against its background, large text 3:1, and UI components and graphical objects 3:1. Low-contrast text is the single most common WCAG failure on the web. Test with a WCAG contrast checker rather than eyeballing it.
8 Use ARIA Only When Native HTML Is Insufficient
The first rule of ARIA: do not use it if a native HTML element or attribute already does the job. aria-label on a real button is fine; ARIA on a plain div does nothing for keyboard support or screen reader announcements until the behavior is also built. Native elements win.
9 Label Every Form Field and Input
Each input needs an associated label, either a visible label element or an accessible name. Placeholder text is not a label. Well-labeled forms also improve conversion and help search engines understand what the form collects.
10 Write Descriptive, Context-Aware Link Text
Link text must make sense out of context, so avoid click here, read more, and learn more. Descriptive anchor text is a WCAG success criterion and a ranking signal. It is also what appears in search results when Google chooses the anchor as the title.
11 Caption and Transcribe Media
Video needs synchronized captions, and audio content needs a transcript. Transcripts are indexable text that gives search engines something to match, effectively converting inaccessible media into searchable content.
12 Respect Reduced Motion Preferences
Honor the prefers-reduced-motion media query by disabling non-essential animation, parallax, and autoplay. Unnecessary motion is a vestibular trigger and a performance cost, which connects directly to Core Web Vitals and LCP.
13 Provide Adequate Touch Target Sizes
Interactive targets should be at least 24 by 24 CSS pixels, with 44 by 44 as the practical WCAG 2.2 guideline for touch. Tiny targets fail users on mobile and inflate accidental taps. Generous hit areas are standard mobile UX anyway.
14 Keep Focus Order in the Visual Order
Keyboard focus should move in the same sequence the page is laid out visually. A layout that shifts elements with CSS order or position but leaves the DOM reading order unchanged disorients screen reader and keyboard users.
15 Run Automated Checks and Screen Reader Tests
Automated tools catch 30-50% of WCAG failures, so pair axe or Lighthouse with manual keyboard walk-throughs and a screen reader pass. Rerun the audit on every release. Automated checks cannot catch everything, but they catch the most common failures cheaply.
Common A11y to SEO Mappings
Every accessibility fix that doubles as a ranking signal.
| Accessibility fix | WCAG criterion | SEO benefit |
|---|---|---|
| Semantic headings | 1.3.1 Info and relationships | Clear topic structure for crawlers |
| Image alt text | 1.1.1 Non-text content | Image SEO and image search ranking |
| Descriptive link text | 2.4.4 Link purpose | Better anchor text signals |
| Reduced motion | 2.3.3 Animation from interactions | Lower LCP and jank, better INP |
| Media transcripts | 1.2.1 Audio-only content | Indexable text from video and audio |
| Labeled forms | 3.3.2 Labels or instructions | Better form comprehension and fills |
Common Accessibility Mistakes
The failures behind most WCAG audit reports.
Building everything from divs
Generic divs with ARIA roles bolted on are harder to build and maintain than native elements that work for free.
Hiding the focus outline
Removing outlines for aesthetics leaves keyboard users unable to see where they are. Restore a strong visible focus ring.
Relying on placeholder as label
Placeholders disappear on input and fail the label requirement. Use a real label element on every field.
Low-contrast text and links
Gray text on white is the most common WCAG failure. Run every palette through a contrast checker.
ARIA on everything
Excessive ARIA that mirrors native semantics creates conflicting announcements. Prefer the native element first.
Deferring testing until launch
Fixing accessibility after launch is expensive. Run automated checks in the pipeline on every commit.
Accessibility Testing Tools
Automate the checks that catch the most common failures.
axe DevTools
The de facto automated accessibility engine, available as a browser extension and in CI pipelines.
FreeLighthouse
Includes an accessibility audit with manual check flags, integrated into Chrome DevTools.
FreeWAVE
Visual overlay that highlights accessibility errors and contrast issues directly on the page.
FreeWebAIM Contrast Checker
Quick WCAG contrast checker for any two colors before you commit a palette.
FreeNVDA or VoiceOver
Screen reader testing to verify how your page is actually announced.
FreePa11y
Command-line accessibility testing that plugs into CI and reports failures by severity.
FreeSiteimprove
Enterprise accessibility monitoring with automatic fixes, reporting, and WCAG compliance tracking.
PaidRelated Checklists
Keep exploring the technical SEO series. Every checklist follows the same structure.
Technical On-Page SEO
Headings, landmarks, and alt text are shared on-page and accessibility work.
Image SEO
Descriptive alt text serves both accessibility and image rankings.
Core Web Vitals and Performance
Interaction responsiveness and visual stability overlap with usability.
E-E-A-T and Entities
Clear, human-first pages build both accessibility and credibility.
Mobile UX
Tap targets and font sizing affect mobile and accessibility equally.
Full Technical SEO Audit
Add accessibility checks to your full audit pass.
Need an Accessibility Audit?
Get professional WCAG 2.2 AA audits and remediation from Clienvora. Our expert team fixes contrast, semantics, and keyboard issues while improving your SEO.
Free consultation. Get a personalized technical SEO audit for your website today. Or download the full checklist PDF.
Accessibility Frequently Asked Questions
Direct answers on WCAG, ADA, and testing.
WCAG 2.2 is the current version of the Web Content Accessibility Guidelines published in October 2023. AA is the compliance level most sites target and most legal actions reference. Level A covers the basics, AA adds contrast and usability requirements, and AAA is rarely practical for full sites.
Screen readers and search bots both consume HTML source. Semantic HTML, alt text, and link text help both equally, and accessibility fixes overlap with Core Web Vitals performance.
4.5:1 for normal text, 3:1 for large text at 18pt or 14pt bold, and 3:1 for UI components and graphical objects per WCAG 2.2 AA.
Only when native HTML cannot express the behavior. The first rule of ARIA is that native elements win. ARIA on a plain div does not add keyboard support by itself.
Yes. Title III applies to places of public accommodation, and courts treat websites as covered. WCAG 2.1 or 2.2 AA is the accepted technical standard.
The WebAIM Million study found 96.3% of the top one million homepages had detectable WCAG failures, with low-contrast text the most common issue.