This article describes what "cookies" are, how they are used, and how to manage them in Firefox.
What is a cookie?
A cookie is information stored on your computer by a website you visit.
In some browsers, each cookie is a small file, but in Firefox, all cookies are stored in a single file, located in the Firefox profile folder.
Cookies often store your settings for a website, such as your preferred language or location. When you return to the site, Firefox sends back the cookies that belong to the site. This allows the site to present you with information customized to fit your needs.
Cookies can store a wide range of information, including personally identifiable information (such as your name, home address, email address, or telephone number). However, this information can only be stored if you provide it - websites cannot gain access to information you didn't provide to them, and they can't access other files on your computer.
By default, the activities of storing and sending cookies are invisible to you. However, you can change your Firefox settings to allow you to approve or deny cookie storage requests, delete stored cookies automatically when you close Firefox, and more.
Cookie settings in Firefox are managed in the OptionsPreferences window's Privacy panel. See Settings for privacy, browsing history and do-not-track for information on these settings.
For instructions on how to use these settings for certain tasks, see:
- Enable and disable cookies that websites use to track your preferences: How to turn cookie storage off or on in Firefox.
- Delete cookies to remove the information websites have stored on your computer: How to remove cookies that have already been stored by websites.
- Block websites from storing site preferences or login status in Firefox: How to block certain websites from storing cookies.
- Disable third-party cookies in Firefox to stop some types of tracking by advertisers: How to block websites other than the one you're currently visiting from storing cookies.
If you are having a problem with Firefox that involves cookies, see:
- Websites say cookies are blocked - Unblock them
- Fix login issues on websites that require a username and password