Cookies are stored on your computer by websites you visit and contain information such as site​ pref​eren​ces ​or logi​n stat​us. This article describes how to block websites from storing cookies in Firefox.

Block cookies for a single site

To set Firefox to block cookies from one website:

1. Go to the website you wish to block from setting cookies in Firefox.
2. Right-clickHold down the Ctrl key while you click within the page and select View Page Info.
3. In the Page Info window, select the Permissions panel.
4. Underneath Set Cookies, remove the check mark from Use Default.
5. Change the setting to Block.
   
   
   
6. Close the Page Info window.
7. Remove any cookies that the website has already set in Firefox. For instructions, see Deleting cookies.

Viewing a list of blocked sites

To see a list of sites that you have blocked from setting cookies:

1. At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click OptionsOn 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 PreferencesAt the top of the Firefox window, click on the Tools menu and 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...

2. Select the Privacy panel.

3. Set Firefox will: to Use custom settings for history.
   
   
   
4. Next to Accept cookies from sites, click Exceptions....

Block cookies for all sites

To set Firefox to block cookies from all websites:

1. At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click OptionsOn 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 PreferencesAt the top of the Firefox window, click on the Tools menu and 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...
2. Select the Privacy panel.
3. Set Firefox will: to Use custom settings for history.
4. Remove the check mark from Accept cookies from sites.
5. Click OK to close the Options windowClick Close to close the Preferences windowClose the Preferences window

To remove cookies that were stored previously, see Deleting cookies.

Block third party cookies

To set Firefox to accept cookies only from the website you're currently visiting, see Disabling third party cookies.