To use Android extensions, you'll need Firefox for Android. To explore Firefox for desktop add-ons, please visit our desktop site.
Run peristent JavaScript and CSS code snippets on any website.
Inspect HTTP response headers for any URL with one click
Instantly convert integers across multiple number bases
Craft semantic git commits with scope body and breaking
Visual progress bar shows how far you have scrolled
Keep your Wi-Fi credentials safe — encrypted local network key storage
Evaluate JavaScript expressions and log results instantly
Customisable dice roller with history and total display
Searchable Git command reference with copy support
Browse search and remove cookies for any domain
Mini pixel art creator with custom colors and export
Check WCAG contrast ratio between any two colors
Convert numbers between decimal hex binary and octal
Build conventional git commit messages with emoji types
Find missing width or height from aspect ratio instantly
Check how strong your password is with live scoring
Highlight your Google search terms on the landing page
Run JavaScript snippets directly in the browser sandbox
Fetch and download site favicons and apple touch icons
Visual CSS box-shadow generator with live preview pane
Generate QR codes for any URL or text instantly
Measure element dimensions by dragging a ruler overlay
Add sites to a blocklist that redirects to a focus page
Instant fuzzy search across all open tabs in any window
Test if any number is prime and list primes up to N
