Local WCAG 2.2 pre-check

Check HTML accessibility risks before launch.

Paste HTML or choose a local file to uncover missing names, document structure problems, keyboard risks, media gaps, and other patterns worth fixing. Then verify color pairs in the built-in contrast lab.

  • Runs in your browser
  • No URL fetch
  • No source upload
  • No account
A clean automated result is not a compliance certificate. Static source checks cannot judge meaning, keyboard behavior, CSS states, screen-reader output, or every WCAG requirement. Use the manual checklist and test the rendered experience with people and assistive technology.
Source audit

Check an HTML document

Use the complete server-rendered HTML when possible. Fragments are accepted, but page-level language, title, H1, and landmark checks may then need to be ignored.

Audit scope
0 / 500,000 bytes
Maximum 500,000 UTF-8 bytes and 25,000 parsed elements. Scripts remain inert; fetch-capable attributes and CSS are masked before parsing.
The file is read locally by this browser and is not uploaded.
Visual check

Solid-color contrast lab

Compare one foreground and background pair using WCAG relative luminance. Test every real component state separately.

Foreground
Background
Large text means at least 24 px regular, or approximately 18.67 px bold.

Readable text matters.

Previewing exactly 16 CSS px at weight 400.

The sample shows only the evaluated foreground, background, size, and weight. Test normal copy, labels, icons, and every interaction state separately.

10.48:1Normal text thresholds
The displayed ratio is conservatively truncated to two decimals, so it never rounds a failing value up to a threshold.
AA text
AAA text
Non-text 3:1
Practical workflow

Turn findings into fixes

  1. Fix detected issues firstThey are high-confidence source patterns such as missing names, titles, language, or iframe labels.
  2. Review context, not just markupAlt quality, heading meaning, table relationships, and focus order require judgment.
  3. Test the rendered interfaceUse keyboard-only navigation, zoom, high contrast, and at least one screen reader.
  4. Retest every stateOpen dialogs, trigger errors, reveal menus, and repeat after meaningful changes.

What this accessibility checker can—and cannot—tell you

Source checks catch preventable mistakes

Missing alternative text, unnamed controls, broken label targets, absent page language, untitled frames, duplicate IDs, and risky focus patterns are useful early signals. Each finding includes a DOM path, a bounded source excerpt, an impact explanation, and a concrete repair direction.

Rendered behavior still needs people

JavaScript state, CSS visibility, focus movement, keyboard traps, reading order, announcements, responsive reflow, captions, and the quality of names cannot be proven from pasted HTML. A result with zero detected issues still requires manual evaluation.

Use standards as the reference

The checks map to WCAG 2.2 and selected W3C techniques. W3C itself notes that no evaluation tool alone can determine conformance.