The One bookmarklet
Install one bookmark and run quick page checks for SEO metadata, mobile-friendly test, screenshots, alt text, and link validation.
Install in 3 steps
1. Show bookmarks bar: Chrome/Edge Ctrl+Shift+B (Mac: Cmd+Shift+B).
2. Drag this button to your bookmarks bar.
3. Open any page and click the bookmark.
Why bookmarklet
A bookmarklet runs from your own bookmarks instead of installing a full browser extension. That means:
No extension permissions or extension store dependency
Works as a lightweight workflow on shared or locked-down environments
Easy to update instantly by replacing one bookmark code
Use it for quick diagnostics. Some checks can still be limited by target-site browser security policies.