Disable third-party cookies in Firefox to stop some types of tracking by advertisers

Revision Information
  • Revision id: 15226
  • Created:
  • Creator: scoobidiver
  • Comment: Removed fx3 content and fx35 tag, fixed nested lists, added Win Fx5 screenshot, added a link to DNT, removed duplicated keyword
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: AliceWyman
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: Yes
  • Readied for localization:
  • Readied for localization by: AliceWyman
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Third-party cookies are cookies that are set by one site, but can be read by another site. For example, when you visit site1.com, it might set a cookie that can be read by site2.com.

Some advertisers use these types of cookies to track your visits to the various websites on which they advertise. If you are concerned about this, you can disable third-party cookies in Firefox.

  • If you are concerned about tracking by advertisers, see also How do I turn on the Do Not Track feature?.
  • Disabling third-party cookies in Firefox can stop some types of tracking by advertisers, but not all.
  • Some websites (e.g. Microsoft's Hotmail, MSN, and Windows Live Mail webmail) use third-party cookies for purposes that are not necessarily privacy concerns, and disabling third-party cookies may cause problems with those sites.

Third-party cookie settings are available in the OptionsPreferences window's Privacy panel:

  1. At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.

    Click the menu button New Fx Menu and choose Options.Preferences.

  2. Select the Privacy panel.

  3. Set Firefox will: to Use custom settings for history.
    Custom History Fx21 WinXP Custom History Fx21 Win7 Custom History Fx21 Mac Custom History Fx21 Linux customhistory38
  4. Uncheck Accept third-party cookies. Disabling Third Party Cookies - Fx5 Win


  5. Click OK to close the Options window.Click Close to close the Preferences window.Close the Preferences window. Close the about:preferences page. Any changes you've made will automatically be saved.