How to Clear Private Data in Mozilla Firefox

It's easy to remove all or some of your browsing history

Official Firefox logo.


Some web browsers take great care to maintain your privacy. Still, you can take steps that contribute to your security. For example, empty the browser cache of web pages and stored passwords as well as clear the browsing history or cookies, particularly if you use a public computer. If you don't clear your private data, the next person using the same computer could see your browsing session.

Firefox updates frequently. The procedures we outline below were tested on Firefox build 68.0b12 (32-bit).

What's in Your Firefox History?

Firefox remembers a lot of information for you to make your browsing experience more pleasant and productive. This information is called your history, and it consists of several items:

  • Cookies store information about the websites you visit.
  • Browsing history is a list of sites you visited.
  • Download history is a list of the files you downloaded.
  • Form history contains information you entered into online forms.
  • Search history includes all the terms you entered into the Firefox search bar.
  • Cache stores temporary files that Firefox downloads from the internet to speed up your browsing experience.
  • Offline Website Data consists of files a website stores on your computer that allow you to use it even when you aren't connected to the internet.
  • Site Preferences are site-specific preferences including permissions for a site such as a pop-up blocker exception.
  • Active Logins occur when you log in at a website that uses HTTP authentication.

How to Clear the Firefox History

Here's how you clear the history, including all or some of the items listed above:

  1. Select Library. It resembles books on a shelf.

    Firefox with the Library button highlighted
  2. Choose History.

    Firefox Library menu with the History option highlighted
  3. From the History menu, select Clear Recent History.

    History menu in Firefox with Clear Recent History highlighted
  4. Select the items to clear, and for a specific time duration. Firefox supports selective deletion based on specific time ranges (the last one, two, or four hours; today; all time) and types of information.

  5. Select Clear Now after you've configured your preferences.

    Clear Recent History menu in Firefox with the Clear Now button highlighted

How to Set Firefox to Automatically Clear the History

Firefox can automatically clear your browser history when you exit the browser, so you don't have to do it manually:

  1. Open the Browser Privacy setting. Go to the address bar, type about:preferences#privacy, and press Enter.

    Firefox with the privacy command highlighted
  2. Scroll down to the Cookies and Site Data section.

    Firefox's privacy screen with the Cookies and Site Data heading highlighted
  3. The Delete cookies and site data when Firefox is closed option, if active, clears cookies and temporary files when the browser application closes. Put a checkmark in the box to enable this activity, or leave it blank to continue with manual maintenance.

    Cookies and Site Data section in Firefox's Privacy & Security settings with the box next to Delete cookies on close highlighted
  4. Close the Settings window when you're done configuring it. It auto-saves, so there's nothing to confirm.