Free Accessibility Bookmarklets

Drag a button to your bookmarks bar, then click it on any webpage to run an instant accessibility check — no install, no sign-up, everything runs locally in your browser.

What is a bookmarklet?

A bookmarklet is a tiny piece of JavaScript saved as a browser bookmark instead of a web address. When you click it, the code runs on the page you are currently looking at — so you can spot-check accessibility on your own site, a client’s site, or any page on the web. Nothing is uploaded or tracked; the code only reads the page in front of you.

How to install

  1. Show your bookmarks bar: Ctrl + Shift + B (Windows / Linux) or Cmd + Shift + B (Mac).
  2. Drag one of the blue buttons below onto your bookmarks bar. (Clicking the button on this page will not do anything useful — it needs to be dragged.)
  3. Open any website, then click the new bookmark. A small A11ytek results panel appears in the top-right corner.
  4. Press Esc, click the close button, or click the bookmark again to clear the highlights.

Prefer to add it by hand? Each tool below has a “Copy the code manually” option — create a new bookmark and paste the code as its URL.

The bookmarklets

Alt-Text Check

Scans every image on the page and flags ones with no meaningful alternative text. Images with a missing alt attribute get a red outline (likely errors); images with an empty alt="" get an amber dashed outline (verify they are truly decorative). A summary panel lists the offending image sources.

⬇ A11ytek Alt-Text Check

Drag the button above to your bookmarks bar (do not just click it here).

Or copy the code manually

Select all (Ctrl/Cmd + A) inside the box, then copy (Ctrl/Cmd + C).

Heading Outline

Shows the page’s heading structure (H1–H6) in reading order, flags a missing H1, skipped levels (e.g. H2 jumping to H4), and empty headings. Each heading is outlined on the page so you can see where it sits.

⬇ A11ytek Heading Outline

Drag the button above to your bookmarks bar (do not just click it here).

Or copy the code manually

Select all (Ctrl/Cmd + A) inside the box, then copy (Ctrl/Cmd + C).

Low-Contrast Text

Checks visible text against its resolved background colour and flags anything below the WCAG 2.1 AA contrast minimum (4.5:1 for normal text, 3:1 for large text). Failing elements are outlined in red and listed with their measured ratio. Text over images or gradients is skipped rather than guessed.

⬇ A11ytek Low-Contrast Text

Drag the button above to your bookmarks bar (do not just click it here).

Or copy the code manually

Select all (Ctrl/Cmd + A) inside the box, then copy (Ctrl/Cmd + C).

Privacy & limitations

These tools run entirely in your browser and never send any data anywhere. They are quick spot-checks, not a substitute for a full audit — automated tools catch only a portion of accessibility issues, and human review is always needed for things like meaningful alt text, logical reading order, and real-world contrast over images.

Need a complete WCAG 2.1 / AODA audit or remediation? Get in touch with A11ytek or request a free report.