Web Accessibility Scanner
Your friendly guide to a web that works for everyone.
With Omi you can check your webpages for accessibility so we can make the web accessible for everyone
About
Making accessibility part of every developer's workflow
Omi A11Y is a free Chrome extension that scans any webpage for WCAG 2.1 A and AA violations right in your browser. No sign-up, no build pipeline changes, just click the extension and instantly see what's broken, why it matters, and how to fix it. Whether you're a developer auditing your own work or a designer checking a client site, Omi turns complex accessibility standards into clear, actionable guidance.
From missing alt text to keyboard traps, every check runs instantly in your browser.
Jump directly to any failing element on the page, no hunting through the source required.
Both conformance levels so you can meet legal requirements and best-practice standards.
No paywalls, no premium tiers, full access for every developer, everywhere.
What Omi Checks
Every check, named and mapped.
25 automated checks across WCAG 2.1 A and AA, each one linked to the exact criterion it covers so you always know why it matters.
| # | Check | WCAG |
|---|---|---|
| AriaLevel A Errors | ||
| 1 | Missing alt text on images | 1.1.1 |
| 2 | Empty links with no accessible name | 2.4.4 |
| 3 | Form inputs without a label | 4.1.2 |
| 4 | Buttons with no accessible name | 4.1.2 |
| 5 | Page missing a title element | 2.4.2 |
| 6 | Click-only elements with no keyboard access | 2.1.1 |
| 7 | Interactive elements removed from tab order | 2.1.1 |
| 8 | Custom widgets missing tabindex | 2.1.1 |
| 9 | Dialogs missing focus management | 2.1.2 |
| 10 | Linked images with empty alt text | 1.1.1 |
| AltoLevel A Warnings | ||
| 1 | aria-label placed on a child element instead of the parent link | 1.1.1 |
| 2 | <html> missing a lang attribute | 3.1.1 |
| 3 | Heading levels that skip (e.g. H2 → H4) | 1.3.1 |
| 4 | Elements with tabindex > 0, disrupting tab order | 2.4.3 |
| 5 | Toggle buttons missing aria-expanded | 4.1.2 |
| 6 | Click handlers with no matching keyboard handler | 2.1.1 |
| 7 | Custom dropdowns missing ARIA keyboard support | 4.1.2 |
| 8 | Images with empty alt whose filename implies content | 1.1.1 |
| InfoLevel A Info | ||
| 1 | Buttons whose label text implies a toggle (menu, dropdown, accordion) but have no aria-expanded | 4.1.2 |
| ContraLevel AA Errors | ||
| 1 | Page missing an <h1> heading | 2.4.6 |
| 2 | Text with color contrast more than 1.5 below the required ratio (4.5:1 normal / 3:1 large) | 1.4.3 |
| NavLevel AA Warnings & Info | ||
| 1 | More than one <h1> on a single page | 2.4.6 |
| 2 | Multiple <main> landmark elements | 1.3.6 |
| 3 | Text with contrast mildly below the required threshold | 1.4.3 |
| 4 | Page with multiple links but no <nav> landmark | 1.3.6 |
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