Firefox
Firefox stores per-profile web content caches to speed up browsing, including HTTP disk cache entries, startupCache bytecode, compiled JavaScript caches, image and media cache files, and GPU shader and graphics caches tied to your current browser build and driver state. When those files become oversized, fragmented, or stale after browser, extension, or graphics driver changes, Firefox can reuse bad local data and show broken page assets or sluggish startup; Kudu removes only those rebuildable cache files while leaving bookmarks, history, saved passwords, cookies, extensions, and profile settings alone.
Why clean Firefox?
- Corrupted HTTP disk cache entries can make sites load old CSS, JavaScript, or images, so pages look broken or keep showing an outdated version until the cache is cleared
- An oversized cache2 directory wastes gigabytes in a busy profile and is often noticed as Firefox using far more disk space than expected
- Stale startupCache and compiled script caches after a Firefox update can lengthen launch time, causing a slow first start while the browser rebuilds optimized code
- Invalid GPU and shader cache files after a graphics driver update can trigger black rectangles, flickering video, or choppy scrolling because old compiled graphics data no longer matches the driver
- Bad image and media cache entries can leave thumbnails, icons, or embedded videos stuck blank even though the same page works after a hard refresh
- Cache databases and SQLite files inside the profile can accumulate page fragmentation over time; VACUUM rewrites the database into a compact layout without deleting rows, which can reduce bloat and improve responsiveness in cache-related metadata stores
- Extension updates can leave cached scripts and assets out of sync with the new version, showing toolbar glitches, missing popup content, or add-ons that only work again after local caches are rebuilt
Cache paths Kudu targets
Windows
%AppData%/Mozilla/Firefox/Profiles |
%LocalAppData%/Mozilla/Firefox/Profiles |
macOS
~/Library/Application Support/Firefox/Profiles |
~/Library/Caches/Firefox/Profiles |
Linux
~/.mozilla/firefox |
~/.cache/mozilla/firefox |
Common questions about Firefox
Download Kudu and reclaim your disk space.
Available on Windows, macOS, and Linux. No account required, no feature gates, no telemetry without consent. All cleaning targets are open source and community-auditable.