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 additional that contribute to your security. It is prudent, for example, to empty your browser's 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 do not clear your private data, the next person using the same computer might catch glimpses of your browsing session.

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

Clearing 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 Firefox's search bar.
  • The 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 Your Firefox History

Firefox redesigned its toolbar and features for 2018. Here's how you clear the history, including all or some of the items listed above:

  1. Click the Library button at the top right of the screen. It resembles books on a shelf. From the fly-out menu, select History.

    Firefox window with the library fly-out menu open
  2. From the History menu, select Clear Recent History.

    Firefox history menu
  3. Select the items you wish to clear, and for a specific time duration, within the pop-up box. Firefox supports selective deletion based on specific time ranges (the last one, two, or four hours; today; all time) and types of information. Click Clear Now after you've configured your preferences.

    Firefox Clear Recent History pop-up window

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 by typing about:preferences#privacy in the address bar. Scroll down to the section titled Cookies and Site Data.

    Firefox privacy-preferences settings window
  2. The Delete cookies and site data when Firefox is closed option, if active, will flush cookies and temporary files when the browser application closes. Put a check mark in the box to enable this activity, or leave it blank to continue with manual maintenance.

  3. Close the settings window when you're done configuring it. It auto-saves, so there's nothing to confirm.