You can let the cookies expire when Firefox is closed to make them session cookies instead of using "Clear history when Firefox closes" to clear all cookies including cookies with an allow exception you may want to keep.

• Options/Preferences -> Privacy & Security
  Cookies and Site Data: [ ] "Delete cookies and site data when Firefox is closed"

You can create a cookie allow exception with the proper protocol (https:// or http://) for websites you want to remember you.

• Options/Preferences -> Privacy & Security
  Cookies and Site Data: "Exception"

Note that you only keep cookies with an allow exception if you use "Delete cookies and site data when Firefox is closed". Deleting cookies otherwise removes all selected cookies.

Ah... I see what I did. I have both the clear history options ticked. Removed the tick from the one under History and it's working now. Thanks for your help.

This fix does not work for me in Firefox 83.0 It stopped working a week ago and i can't fix it. Why?

Firefox 82+ comes with a "Redirect Tracking Protection" feature to purge tracking cookies for websites automatically.

You can disable the feature to purge tracking cookies automatically via the about:config page.

• privacy.purge_trackers.enabled = false

You can open the about:config page via the location/address bar. You can click the button to "Accept the Risk and Continue".

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

I want to keep cookies for signing on to trusted sites (e.g. brokerage accounts) after I close Firefox; the rest I want deleted.

The tools that you provide are buried in the bowels of Firefox and might work great if you are computer savvy, which most of us are not. Can't you make this like the most simple thing on the planet?? I have a cookie manager that has a drop down box that has options like "Delete current site cookies." Can't you come up with something like "Keep existing site cookies after Firefox closes"?

I am really interested in only keeping "sign-on" cookies- those that show my PC is trusted, not all of the cookies a site might set on my PC.

I want to keep cookies for signing on to trusted sites (e.g. brokerage accounts) after I close Firefox; the rest I want deleted. The tools that you provide are buried in the bowels of Firefox and might work great if you are computer savvy, which most of us are not. Can't you make this like the most simple thing on the planet?? I have a cookie manager that has a drop down box that has options like "Delete current site cookies." Can't you come up with something like "Keep existing site cookies after Firefox closes"? I am really interested in only keeping "sign-on" cookies- those that show my PC is trusted, not all of the cookies a site might set on my PC.

This is precisely what I would like to do. I'm using Firefox 84.0.2. Anyone know if there is some way to do it?

I confirm the problem

- Unchecked "cookies" and "site preferences" in "Clear history...." - Enabling "Delete cookies and site data when Firefox is closed" - Adding exceptions for selected sites. - set privacy.purge_trackers.enabled = false (I doubt this is required)

No way , all cookies are still purged when firefox close.....

Using FF 87.0

I confirm the problem - Unchecked "cookies" and "site preferences" in "Clear history...." - Enabling "Delete cookies and site data when Firefox is closed" - Adding exceptions for selected sites. - set privacy.purge_trackers.enabled = false (I doubt this is required) No way , all cookies are still purged when firefox close..... Using FF 87.0

I have the same problem !