Why Aren't Cookies Deleted after Closing Private Browsing Windows?
Here's the things I did:
1) Opened a New Private Window from a regular window. 2) Logged into a secure website in the Private Window. 3) Closed the Private Window. 4) Cleared all history. 5) Open a new Private Window.
The new Private Window contained cookies from the previous private window even after I cleared all history.
I don't see the cookies when I go to Show Cookies, but they must be there because the Private Window has my login information.
Why are cookies available across Private browsing sessions even after clearing all history? This seems to be a major bug.
All Replies (5)
All private windows share a single cookie jar, but once you have closed all private windows, that jar should be destroyed.
One possible reason for this not working as expected is if Firefox is set to start up automatically in private browsing mode. In that case, all windows are private so there is only one cookie jar for the entire session. If you do not see the white-on-purple mask icon on the title bar in a private window, this is worth investigation further:
"3-bar" menu button (or Tools menu) > Options > Privacy
If this panel says "Firefox will: Never remember history" then Firefox will use automatic private browsing mode.
To change that, you would change the dialog to "Firefox will: Use custom settings for history" and then uncheck the box for Automatic private browsing.
Another potential issue is the use of Flash Local Storage Objects, sometimes called Supercookies. To test this possibility, you can set the Flash plugin to "Ask to Activate" and not approve it for the sites you visit in the private window(s). If they are unable to identify you on the later visit, this could be their means of identifying you.
To change the default permission for Flash, you can use the Add-ons page. Either:
- Ctrl+Shift+a
- "3-bar" menu button (or Tools menu) > Add-ons
In the left column, click Plugins. Then find Shockwave Flash and change it from "Always Activate" to "Ask to Activate".
When you visit a site that wants to use the Flash, you should see a notification icon in the address bar (looks like a small Lego block) and one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page.
What do you mean with login information (the Private Window has my login information)?
Are you still logged on (remembered)?
The Password Manager still works in PB mode, only you can't store new passwords and passwords are not auto-filled.
I'm not starting automcatically in Private Browsing mode. I don't have Flash installed. I am not using the Password Manager.
What I mean by "has my login information" is when I start typing in the input box the username I typed yesterday is in the dropdown. So the form history is not cleared properly when I Clear Recent History.
You can rename (or delete) the formhistory.sqlite file in the Firefox profile folder to remove all saved form data. If you want to make sure that no passwords are stored as well you can delete the logins.json and signons.sqlite file (may not be present) and key3.db file as well.
You can use this button to go to the currently used Firefox profile folder:
- Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
- http://kb.mozillazine.org/Profile_folder_-_Firefox
Also, if you do not want Firefox to remember stuff you type into forms (non-password fields), you can turn off that feature on the Privacy Panel in the Options dialog:
"3-bar" menu button (or Tools menu) > Options > Privacy
With the selector set to "Firefox will: Use custom settings for history" uncheck the box for "Remember search and form history".