How to Clear Firefox's Cache on Mac (Properly)

Firefox is the lightest of the major browsers when it comes to cache, but lightest is relative. After a few months of moderate use, Firefox’s profile folder still typically hits 500MB to 2GB on most Macs. Most of that is cache and can be cleared without losing bookmarks, history, or saved passwords.

Here’s how to do it properly on macOS Sonoma 14 and Sequoia 15, including the parts most articles skip.

Where Firefox stores cache on Mac

Firefox uses a profile system, so caches live inside whichever profile you’re using:

• ~/Library/Caches/Firefox/Profiles/[random].default-release/cache2/ — the main HTTP cache
• ~/Library/Application Support/Firefox/Profiles/[random].default-release/storage/ — IndexedDB and local storage
• ~/Library/Application Support/Firefox/Profiles/[random].default-release/startupCache/ — startup optimization data

The [random] is a random 8-character string Firefox generates when it creates the profile. Yours might be abc12def.default-release or similar.

There’s also ~/Library/Application Support/Firefox/Crash Reports/ which keeps every crash report ever, often without limit.

The standard in-app clear

This handles 90% of cases:

1. Open Firefox.
2. Click the menu (three lines, top right) → Settings.
3. Go to Privacy & Security.
4. Scroll to Cookies and Site Data.
5. Click Clear Data.
6. Check Cached Web Content (and optionally Cookies and Site Data if you want a deeper clean).
7. Click Clear.

Done. The cache folders empty out, Firefox keeps working, you stay logged into sites if you only checked Cached Web Content.

If you want a full reset: also check Cookies and Site Data, but expect to log back into every site afterward.

Clearing cache for a specific site only

Sometimes you don’t want to nuke everything — just one misbehaving site.

1. Visit the site in question.
2. Click the padlock icon next to the URL.
3. Click Clear cookies and site data.
4. Confirm.

Reloads and reauthenticates just that site. Useful if a single web app is acting weird and a full cache clear feels heavy-handed.

Manual cache clearing (when in-app isn’t enough)

If you’ve uninstalled Firefox but the cache is still sitting around, or you want to verify it’s actually gone:

1. Quit Firefox completely (Cmd+Q).
2. Open Finder, press Cmd+Shift+G.
3. Paste ~/Library/Caches/Firefox/.
4. Move the entire Profiles folder inside to the Trash (or just the cache2 subfolder of your profile).
5. Empty the Trash.

The cache will rebuild itself on next launch. Nothing important lives in ~/Library/Caches/Firefox/ — bookmarks, history, and passwords are in ~/Library/Application Support/Firefox/.

Don’t dig through ~/Library yourselfSweep knows where every app stores its cache. Free download for Mac →

What about the storage and IndexedDB folders?

~/Library/Application Support/Firefox/Profiles/[profile]/storage/ holds IndexedDB databases for sites that use them — Gmail, Notion, Figma, anything that runs as a web app and stores data locally. This isn’t cache exactly; it’s persistent site data.

Clearing it logs you out of those sites and resets any locally-stored state. Don’t delete it unless you specifically want that. The in-app Clear Data option handles this more cleanly.

Refreshing Firefox (the nuclear option)

If Firefox is broken in some weird way that a cache clear won’t fix, Mozilla provides a “Refresh Firefox” feature that resets settings, removes add-ons, and clears caches while preserving bookmarks, history, passwords, and form fill data.

1. Type about:support in the address bar.
2. Click Refresh Firefox in the top right.
3. Confirm.

Firefox creates a new profile, copies your important data over, and restarts fresh. Old profile is moved to Desktop in case you need anything from it.

This is heavy-handed but solves a lot of “Firefox is being weird” problems.

Multiple Firefox profiles

If you use Firefox profiles for work/personal separation (via firefox -P or the profile manager), each profile has its own cache folder. Clearing one doesn’t affect the others.

To see your profiles:

1. Type about:profiles in the address bar.
2. Each profile has its own Local Directory and Root Directory listed.

Profiles you’ve abandoned but never deleted are pure overhead. Click Remove to clean them up.

Clearing Firefox cache via Terminal

For the command-line inclined:

quit Firefox first
rm -rf ~/Library/Caches/Firefox/Profiles/*/cache2

That clears the main HTTP cache for every Firefox profile in one go. Other folders preserved.

There’s a faster waySweep finds and clears caches across every app you use, all at once. Try Sweep free →

When clearing Firefox cache helps

• Pages loading old versions of stylesheets or scripts. Hard refresh (Cmd+Shift+R) often handles this, but a cache clear is the bigger hammer.
• Login loops or session issues on specific sites. Clear cookies for that site, not the whole cache.
• Firefox feels slow on startup. Clear startupCache specifically.
• Disk space pressure. Cache folder is a quick few hundred MB to a couple GB.

When it doesn’t help: anything related to extensions, settings, or actual Firefox bugs. Those need a profile refresh or version update.

Clearing Firefox vs. other browsers

Each browser caches in its own neighborhood:

• Chrome: ~/Library/Caches/Google/Chrome/ and ~/Library/Application Support/Google/Chrome/Default/Cache
• Safari: ~/Library/Containers/com.apple.Safari/Data/Library/Caches/
• Edge: ~/Library/Caches/com.microsoft.edgemac/ and ~/Library/Application Support/Microsoft Edge/
• Brave: ~/Library/Application Support/BraveSoftware/Brave-Browser/Default/Cache

If you use multiple browsers (most people do at this point), you’ve got cache in 3-5 different folders. Each needs its own clear.

Worth automating?

For Firefox alone, no — the in-app Clear Data option works fine. For maintaining a Mac with three browsers, ten Electron apps, and a few years of macOS accumulation, automating is the only way it actually gets done with any consistency.

Sweep handles every browser, every Electron app, and every system cache folder in one scan. It identifies what’s safe to remove, shows you the list, and clears it once you confirm. Free download — works on macOS Sonoma 14 and Sequoia 15.

Bottom line

Firefox’s cache lives at ~/Library/Caches/Firefox/Profiles/. The cleanest way to clear it is via Settings → Privacy & Security → Clear Data. The full path approach works too if you want to verify everything’s gone or you’ve already removed the app.

Don’t touch the Application Support folder unless you know what you’re doing — that’s where bookmarks, history, and passwords live.