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restore old profile

  • 2 replies
  • 1 has this problem
  • 23 views
  • Last reply by cor-el

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I just installed the esr version of Firefox. I did not think that I would lose all my bookmarks, add-on, etc. Is there a way to revert back to the standard version with all my old data? Or in looking at the profiles I see a default profile, a default-esr profile, and a default-release profile. This latter profile seems to have my old data when I open the folders and look around. However, when I try to open that profile in new window it says something about opening an old version and losing data and creating a new profile. When I do that, I still get a fresh browser with none of my data.

I just installed the esr version of Firefox. I did not think that I would lose all my bookmarks, add-on, etc. Is there a way to revert back to the standard version with all my old data? Or in looking at the profiles I see a default profile, a default-esr profile, and a default-release profile. This latter profile seems to have my old data when I open the folders and look around. However, when I try to open that profile in new window it says something about opening an old version and losing data and creating a new profile. When I do that, I still get a fresh browser with none of my data.

All Replies (2)

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It is likely ESR created its own profile. Note: Different versions of firefox require their own profiles because of compatibility issues.

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Firefox 67 and newer use a dedicated profile for each Firefox installation and lock this profile to prevent other Firefox installations from using this profile.


You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. Note that best is to avoid copying a full profile folder.


  • 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)

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