Firefox - Automatically delete cookies

October 2016

The procedure to set a Cookie Retention Policy (number of days after which cookies will automatically be cleared) under Firefox is as follows:
  • In the address bar type "about.config" and press Enter
  • In the Filter field search for:
    • network.cookie.lifetimePolicy
    • Double click on this entry and set its value to "3"
    • When the value is set to 3, then the cookies will be kept according to the number of days defined in the entry below.
  • Next search for this entry:
    • network.cookie.lifetime.days
    • Double click on this entry to change its value (representing the number of days).
  • Close the about:config window.
  • Restart Firefox.

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