Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox storing cookies and site data even in private mode. How do I stop this?

  • 7 replies
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

more options

After the latest update Firefox stores cookies and site data even in always private and the content blocking set to custom with everything set it the highest settings. Example i can check my email at outlook com then sign out click forget, then close the browser. then open it and it loads my email account without signing in. The only way it can do that is, the browser is storing cookies and site data. the only way to prevent it from doing this is to do everything i described then open the privacy settings and clear cookies, and site data and clear history, two times. Firefox like this is the most unsecured browser. it was a lot better before all these changes. It was a good idea, but it's caused a lot of troubles with security issues for me.

After the latest update Firefox stores cookies and site data even in always private and the content blocking set to custom with everything set it the highest settings. Example i can check my email at outlook com then sign out click forget, then close the browser. then open it and it loads my email account without signing in. The only way it can do that is, the browser is storing cookies and site data. the only way to prevent it from doing this is to do everything i described then open the privacy settings and clear cookies, and site data and clear history, two times. Firefox like this is the most unsecured browser. it was a lot better before all these changes. It was a good idea, but it's caused a lot of troubles with security issues for me.

Modified by Bobcat

All Replies (7)

more options

Your ‘logged-in’ status is stored in special cookies. If the cookie is removed, you are logged out.

Did you sign out when you last used that website in normal Firefox?

more options

Thank You For Your Reply.

I don't sign out of Firefox. I always use the strictest privacy settings all the time. I always check to see if there are cookies and/or site data stored in the browser before, I go to another website. I also close the browser, then open a new browser before going to the next website. There is always between 40kb and 4mb stored in the browser.

more options

When using 'Private Mode,' all data is saved in a special folder until the browser closes. Then the folder is removed.

This, however, has nothing to do with any data already saved. Go to the website and sign out.

Is the problem still there?

more options

If clearing cookies didn't help then It is possible that the cookies.sqlite file in the Firefox profile folder that stores the cookies got corrupted.

  • rename/remove cookies.sqlite (cookies.sqlite.old) and if present delete cookies.sqlite-shm and cookies.sqlite-wal in the Firefox profile folder with Firefox closed in case cookies.sqlite got corrupted.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:preferences page.


You can remove all data stored in Firefox from a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History").

Using "Forget About This Site" will remove all data stored in Firefox from this domain like history and cookies and passwords and exceptions and cache, so be cautious. If you have a password or other data from that domain that you do not want to lose then make sure to backup this data or make a note.

You can't recover from this 'forget' unless you have a backup of involved files.

If you revisit a 'forgotten' website then data from that website will be saved once again.

more options

I found out what this data is. Its Google, whenever i open the browser google somehow places a folder that has 4 cookies files in it one to track my browsing activity, one to target image, and text ads, one to target video ads one is to collect my search history. I delete this folder and it respawns. Is there anyway to stop google from placing this folder in Firefox's cache?

Thank You.

more options

Google cookies are required in order to update the phishing protection data. These cookies are hidden from the Firefox Cookie Manager (appid is not 0) and are best left alone.


Some Google cookies are used for the safe browsing component (phishing protection) and you can't remove these special cookies permanently.