What clearing your cache does

Your cache is a folder where Firefox stores copies of web pages, images, and files you've visited. Over time it fills up and can slow your browser down or cause pages to load incorrectly. Clearing it removes those stored copies and frees up space on your computer.

When you clear the cache, Firefox will reload pages fresh the next time you visit them instead of pulling them from storage. This takes a few extra seconds per page but fixes most problems where a site looks broken or won't update properly.

Key Takeaways

  • You can clear your cache in Firefox through the Settings menu in about 30 seconds using the keyboard shortcut Ctrl+Shift+Delete (or Command+Shift+Delete on Mac).
  • The "Clear Recent History" window lets you choose what time period to clear — just today, the last hour, or everything — so you don't have to delete older data if you don't want to.
  • Clearing your cache will log you out of most websites, so have your passwords ready or use a password manager before you start.
  • If a website still looks broken after clearing your cache, try closing Firefox completely and opening it again, or try the site in a private window.

Clear your cache using the keyboard shortcut

The fastest way is to use your keyboard. Press Ctrl+Shift+Delete on Windows or Linux, or Command+Shift+Delete on Mac. A window titled "Clear Recent History" will open immediately.

At the top, you'll see a dropdown that says "Time range to clear." Click it and choose how far back you want to go. Select "Everything" if you want to clear all cached data, or pick a shorter time period like "Last Hour" or "Last 2 Hours" if you only want to remove recent files.

Make sure the checkbox next to "Cache" is checked — it should be by default. You can leave the other boxes checked too; they won't hurt anything. Then click the blue "Clear Now" button at the bottom right.

Clear your cache through the Firefox menu

If the keyboard shortcut doesn't work, you can reach the same window through the menu. Click the three horizontal lines (called a hamburger menu) in the top right corner of Firefox.

Scroll down and click "Settings." On the left side, click "Privacy & Security." Scroll down until you see a section called "Cookies and Site Data." Click the button that says "Clear Data."

A smaller window will pop up. Make sure "Cached Web Content" is checked, then click "Clear." This clears only your cache, not your cookies or other data — if you want to clear those too, check those boxes as well before clicking.

What to expect after clearing your cache

After you clear your cache, Firefox will log you out of most websites. When you visit a site you normally stay logged into, you'll see the login page instead. This is normal and happens because login information is stored separately from cached pages.

The first time you visit a website after clearing cache, it may load slightly slower than usual because Firefox has to download all the images and files fresh. After that first visit, your cache will start building up again and pages will load at normal speed.

If a website still looks broken or won't load correctly after clearing your cache, try closing Firefox completely (not just closing the window — use File > Exit or Command+Q on Mac) and opening it again. If that doesn't work, open the site in a private window by pressing Ctrl+Shift+P (or Command+Shift+P on Mac).

When to clear your cache

You don't need to clear your cache on a schedule. Only do it when you notice a problem — a website looks wrong, a page won't update, or your browser feels sluggish. For most people, clearing cache once every few months is plenty.

If you want Firefox to clear your cache automatically every time you close the browser, you can set that up. Go to Settings > Privacy & Security, scroll to "Cookies and Site Data," and check the box that says "Delete cookies and site data when Firefox is closed." This keeps your cache from building up, though it means you'll have to log back into sites each time you restart Firefox.

Clearing cache on different Firefox versions

These steps work on Firefox for Windows, Mac, and Linux. The menu layout is the same across all three. If you're using Firefox on your phone or tablet, the process is slightly different — tap the three dots at the bottom right, go to Settings, tap "Delete Browsing Data," and choose what you want to clear.

If you're using an older version of Firefox from several years ago, the menu locations might be slightly different, but the general idea is the same: look for "Clear History," "Clear Cache," or "Privacy" in the main menu. If you haven't updated Firefox in a long time, consider updating it — older versions can have security problems.

Frequently Asked Questions

Will clearing my cache delete my passwords?

No. Passwords are stored separately from your cache. If you want to keep your passwords but clear everything else, uncheck "Cookies and Site Data" and "Autofill Data" before clicking Clear. Only "Cached Web Content" needs to be checked to clear your cache.

What's the difference between cache and cookies?

Cache stores copies of images and files from websites so they load faster next time. Cookies store small pieces of information like your login status or preferences. Clearing cache won't log you out, but clearing cookies will. You can clear one without the other.

Why does a website still look broken after I clear my cache?

Sometimes the problem isn't on your computer — it's the website itself or your internet connection. Try closing Firefox completely and reopening it, or try the site in a private window. If it still doesn't work, the website might be having problems on their end.

Can I clear cache for just one website instead of everything?

Not easily in Firefox. You can clear all cache or nothing. If you only want to clear one site, try opening it in a private window, which doesn't use cache at all. Or clear all your cache and then revisit the sites you use most so Firefox rebuilds their cache.

How much space will clearing my cache free up?

It depends on how long you've been using Firefox and how many sites you visit. For most people it's between 100 megabytes and a few gigabytes. You can see how much space your cache is using before you clear it — in the "Cookies and Site Data" section of Settings, Firefox shows the size.