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 enable and disable cookies in Firefox.

Cookie Settings

1. At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
2. Select the Privacy panel.
3. Set Firefox will: to Use custom settings for history. 
4. Choose how long cookies are allowed to be stored:
   • Keep until: they expire: Each cookie will be removed when it reaches its expiration date, which is set by the site that sent the cookie.
   • Keep until: I close Firefox: The cookies that are stored on your computer will be removed when Firefox is closed.
   • Keep until: ask me every time: Displays an alert every time a website tries to send a cookie, and asks you whether or not you want to store it.
5. Click OK to close the Options window