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password recovery from old hard drive

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  • 1 has this problem
  • 14 views
  • Last reply by cor-el

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I had a laptop die on me suddenly without knowing about Firefox sync, the laptops hard drive still worked but I didn't have a way to access it for about 10 months until now. on a new laptop I have set up a new Firefox profile and either set up new passwords or or opened new accounts on some of the websites but a lot of old logins and browsing data, and bookmarks. now that I can access the old profile on the old hard drive I was trying to see if I could just recover missing passwords or data from the old to new profile but on the support website all I can find seems to be how to overwrite the the new profile with the old one which would mean losing a chunk of new passwords and data. it is also unclear whether any new backup or syncs of the new profile would remain or be wiped with the overwrite, is there a way to view the old profiles data to recover parts piecemeal or is the only option to overwrite the new profile. I apologize if this is a lack of computer literacy.

I had a laptop die on me suddenly without knowing about Firefox sync, the laptops hard drive still worked but I didn't have a way to access it for about 10 months until now. on a new laptop I have set up a new Firefox profile and either set up new passwords or or opened new accounts on some of the websites but a lot of old logins and browsing data, and bookmarks. now that I can access the old profile on the old hard drive I was trying to see if I could just recover missing passwords or data from the old to new profile but on the support website all I can find seems to be how to overwrite the the new profile with the old one which would mean losing a chunk of new passwords and data. it is also unclear whether any new backup or syncs of the new profile would remain or be wiped with the overwrite, is there a way to view the old profiles data to recover parts piecemeal or is the only option to overwrite the new profile. I apologize if this is a lack of computer literacy.

All Replies (1)

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You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. For the passwords you need logins.json and key4.db. Note that best is to avoid copying a full profile folder.

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


  • bookmarks and history: places.sqlite
  • favicons: favicons.sqlite
  • bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
  • cookies.sqlite for the Cookies
  • formhistory.sqlite for saved autocomplete Form Data
  • logins.json (encrypted logins;32+) and key4.db (decryption key;58+) for Passwords saved in the Password Manager
    key3.db support ended in 73+; to use key3.db in 58-72, make sure to remove key4.db
  • cert9.db (58+) for (intermediate) certificates stored in the Certificate Manager
  • persdict.dat for words added to the spell checker dictionary
  • permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
  • sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)