AltCatch - Find Missing Alt Text & Broken Links

About

Find every missing alt text and broken image on any web page — then export the whole report as clean Markdown in one click.

AltCatch is a developer-first accessibility and SEO auditor that runs entirely inside your browser. Open any page, run an audit, and get a severity-grouped checklist you can copy, download, or paste straight into a pull request, Linear ticket, or Notion doc.

What AltCatch catches
✓ Images with no alt attribute at all (a WCAG 2.2 failure)
✓ Broken images — 404s and load failures, verified with lightweight HEAD requests
✓ Placeholder alt text like "image", "untitled", or the raw filename
✓ Whitespace-only alt attributes that screen readers silently skip
✓ Decorative images using alt="" (shown collapsed, for context)

How it works
1. Click the AltCatch icon or open the side panel on any page.
2. AltCatch scans every <img> in the DOM and resolves its real source.
3. Broken images are verified asynchronously — no heavy downloads of the actual files.
4. Results stream into a grouped checklist with a live health breakdown.
5. Export to Markdown or copy to clipboard. Done.

Built for
✓ Web developers shipping accessible HTML
✓ SEO specialists auditing image SEO and image search visibility
✓ Accessibility auditors documenting WCAG 2.2 compliance
✓ QA testers writing reproducible bug tickets

Why AltCatch
• Markdown export drops straight into GitHub, Linear, Notion, or PR descriptions — no reformatting.
• Severity classification beyond "missing alt" — catches lazy, placeholder, and decorative cases other tools miss.
• Audit history so you can re-check a page after a fix.
• No account, no signup, no upload. Open it and audit.

Privacy
AltCatch runs 100% locally in your browser. We DO NOT collect, transmit, store, or sell any data. No analytics, no telemetry, no external servers. The only network calls AltCatch makes are HEAD requests to the same image URLs the page already loads, to verify they resolve.

Permissions used
• activeTab + scripting — only on the page you choose to audit
• sidePanel — to render the audit UI in Chrome's side panel
• storage — to keep your audit history locally on your device

Support
Questions, bugs, or feature requests? Reach out at [email protected].

Install AltCatch and ship pages with zero missing alt text.