Clear your cache in Firefox in three steps

To clear your cache in Firefox, open the menu (three horizontal lines in the top right), select Settings, go to Privacy & Security, scroll to Cookies and Site Data, and click Clear Data. A window will pop up — make sure "Cached Web Content" is checked, then click Clear. Your cache is now empty.

Clearing cache removes temporary files Firefox stores from websites you visit. These files load pages faster the next time you visit, but they also take up disk space and can sometimes cause pages to display incorrectly. Most people clear cache when a website looks broken, loads slowly, or when they want to free up storage space.

The process takes about 30 seconds and works the same way on Windows, Mac, and Linux. You can also set Firefox to clear cache automatically every time you close the browser.

Key Takeaways

  • Open Firefox menu, go to Settings, then Privacy & Security, then scroll to Cookies and Site Data to find the Clear Data button.
  • Check the box next to "Cached Web Content" before clicking Clear to remove only cache, not passwords or other saved information.
  • You can set Firefox to clear cache automatically when you close the browser by checking "Delete cookies and site data when Firefox is closed" in the same section.
  • Clearing cache fixes many common problems like pages that won't load correctly, images that don't display, or websites that run slowly.

Step-by-step: Clear cache right now

Step 1: Open the Firefox menu. Look for the three horizontal lines (called a hamburger menu) in the top right corner of your Firefox window. Click it.

Step 2: Click Settings. In the menu that drops down, you will see Settings near the bottom. Click it. A new tab will open showing your Firefox settings.

Step 3: Go to Privacy & Security. On the left side of the Settings page, click the words "Privacy & Security". The page will scroll to show privacy options.

Step 4: Find Cookies and Site Data. Scroll down the Privacy & Security page until you see a section called "Cookies and Site Data". Under it, you will see a button that says "Clear Data".

Step 5: Check the right box. Click "Clear Data". A small window pops up with checkboxes. Make sure the box next to "Cached Web Content" has a checkmark. You can uncheck "Cookies and Site Data" if you want to keep your passwords and login information — clearing cache alone will not remove those.

Step 6: Click Clear. Click the blue "Clear" button. Firefox removes your cache immediately. You can close the Settings tab and go back to browsing.

What gets deleted when you clear cache

Cache includes images, scripts, and other files that websites store on your computer. When you visit a website again, Firefox loads these files from your computer instead of downloading them again, which makes the page load faster. Over time, cache can grow to several hundred megabytes.

When you clear cache, Firefox deletes these temporary files but leaves your passwords, bookmarks, and browsing history untouched — unless you specifically check those boxes in the Clear Data window. This is why it is safe to clear cache without worrying about losing your login information.

If you only want to clear cache from a specific website, you can right-click on the website name in your history and select "Forget About This Site". This removes cache, cookies, and history for just that one site.

Set Firefox to clear cache automatically

You can tell Firefox to clear cache every time you close the browser. This way you do not have to remember to do it manually. Go back to Settings > Privacy & Security, and scroll to the Cookies and Site Data section. Check the box that says "Delete cookies and site data when Firefox is closed".

When this setting is on, Firefox clears cache, cookies, and site data each time you fully close the browser — not just when you close a tab. Your passwords and bookmarks stay, but temporary files are removed. This is useful if you use a shared computer or want to keep your browsing private.

You can also choose which sites are exceptions to this rule. In the same section, click "Manage Exceptions" to add websites whose cache you want to keep. For example, you might want to keep cache for your email site so it loads faster, but clear cache for everything else.

When to clear cache and when not to

Clear cache when a website looks broken, images do not load, or a page loads very slowly even though your internet connection is fast. Outdated cache files can cause these problems. Clearing cache forces Firefox to download fresh files from the website, which usually fixes the issue.

You should also clear cache if you are running low on disk space. Cache can take up hundreds of megabytes over time, especially if you browse frequently. Clearing it frees up that space without affecting your ability to use Firefox.

Do not clear cache if you want websites to load as fast as possible. Cache exists to speed up loading times. If you clear it often, websites will load slower because Firefox has to download all files fresh each time. A good balance is clearing cache once a month or when you notice a problem.

Troubleshooting: Cache still seems to be there

If you clear cache but a website still looks broken or loads slowly, the problem might not be cache. Try closing Firefox completely and opening it again. Sometimes a website's code is stuck in Firefox's memory even after cache is cleared.

If that does not work, try clearing cache again but this time also check the box for "Cookies and Site Data". Some websites store information in cookies that can cause display problems. Clearing both cache and cookies usually solves stubborn issues. You will have to log back into websites after doing this.

If a specific website keeps having problems, try the "Forget About This Site" option instead of clearing all cache. Right-click the website in your history and select it. This removes everything Firefox stored for just that site without touching your other data.

Frequently Asked Questions

Will clearing cache delete my passwords?

No. Passwords are stored separately from cache. When you clear cache, Firefox only removes temporary files from websites. Your saved passwords stay unless you specifically check the "Cookies and Site Data" box in the Clear Data window. If you do check that box, you will have to log back into websites.

How much space does cache take up?

Cache size varies depending on how much you browse and which websites you visit. It can range from 50 megabytes to several hundred megabytes. You can see your cache size in Settings > Privacy & Security under Cookies and Site Data — it shows the amount right before the Clear Data button.

Can I clear cache for just one website?

Yes. Right-click any website in your browsing history and select "Forget About This Site". This removes cache, cookies, and history for only that site. Your data for other websites stays the same.

What is the difference between cache and cookies?

Cache stores images and files to make pages load faster. Cookies store information like your login details and preferences. Clearing cache does not remove cookies unless you check that box. You can clear them separately or together depending on what you need.

Should I clear cache before or after updating Firefox?

You do not need to clear cache before updating. Firefox updates do not depend on cache. However, if you experience problems after an update, clearing cache is a good troubleshooting step to try.