I'm trying to remove my certificates going to Preferences > Advanced > Encryption > View Certificates. Then I select the certificates I want to remove and delete them.

But when I go again to the list, the certificates I had removed are still there.

Any idea?

FF 3.6.10.



  • Which tab are you removing certificates from? (You cannot remove built-in authorities; you can only mark them as "untrusted".) Mar 4, 2011 at 16:10
  • I'm having the same problem in Firefox 80.0.1 for Ubuntu. Sep 19, 2020 at 17:47

3 Answers 3


It's a known bug in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=454782

One workaround is to disable all trust for the certificates instead of removing them.

Another workaround is to remove cert9.db from the Firefox profile directory. Firefox will recreate it with builtin certificates only.


netsekure.org shows how to do this right:


He also found he could reduce his CA count from 100+ to 10. As always YMMV


I'm not sure it's the same case, but for those who are in my situation and come across this post, maybe my answer will be useful. I use Firefox on Windows and was deleting some of my certificates as follows:

Settings → Privacy & Security → Security → View Certificates → Your Certificates

However, when I closed my window and reopened it, they kept coming back...

I didn't understand why until I realized that they were "OS Client Cert Token" certificates.

So I just had to delete them in my Windows certmgr. I deleted it in User\Personal\Certificates, then the deletion worked in Firefox.

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