I installed FF Quantum (58.0b4) and imported a previous backup created with Mozbackup. Bookmarks and history were imported correctly while passwords and saved logins were not. I copied key3.db and logins.json containing passwords from my laptop and pasted them in my PC with the new FF Quantum, but this didn't solved.

How can I import saved passwords?


  • From the release notes I understand that there are changes to the profile which aren't compatible with the old version. I have got the same problem but haven't found a way to restore my logins. – Jérémie Bertrand Nov 20 '17 at 19:22

Well, I forgot to write that I installed the developer version. As the classic Firefox seems to have the same functions the developer edition has, I uninstalled the dev edition and went back to classic. In this way I solved the problem.


Sync the passwords to a Firefox account using the old version. Then sync them into a new profile within the new version of Firefox Quantum. It worked for me using v53.0 b4 (regular) to v58.0 b4 (developer edition).

Firefox account / Sync can be found under "Menu/Tools > Options > etc..."


For those of us who cringe at the thought of syncing passwords online:

  • Update the source Firefox to the latest version
  • Install the target Firefox, enable password storage with same master password as the source Firefox then close Firefox
  • Copy and overwrite these files: cert8.db, cert9.db, key3.db, key4.db, secmod.db, handlers.json, logins.json
  • Start Firefox and check saved logins

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.