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My sync might have gotten lost

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  • Last reply by cor-el

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I just migrated to linux and I've been trying to recover all the stuff I'm used to on windows. The first thing is of course the browser with all my favorite extensions and obviously bookmarks. The first problem was that I had to use password recovery to login into my Firefox account. But when I tried it, there was no option to use the sync recovery key. And from what I understand mine was old (different format). I logged in and setup the sync anew. Before this there was no problem jumping from one windows version to another. I never needed to recover my sync profile. I just logged in and it worked.

So here's the question. Did I just lose all my synchronized stuff or is there still a chance for recovery?

I just migrated to linux and I've been trying to recover all the stuff I'm used to on windows. The first thing is of course the browser with all my favorite extensions and obviously bookmarks. The first problem was that I had to use password recovery to login into my Firefox account. But when I tried it, there was no option to use the sync recovery key. And from what I understand mine was old (different format). I logged in and setup the sync anew. Before this there was no problem jumping from one windows version to another. I never needed to recover my sync profile. I just logged in and it worked. So here's the question. Did I just lose all my synchronized stuff or is there still a chance for recovery?

Chosen solution

If the account password was changed without the recovery keys, the data can't be recovered unfortunately. This has to do with how your data is encrypted. It's encrypted using the Firefox Account password. When the Firefox Account password is changed, it no longer matches the password needed to decrypt the data. Since the Firefox Account system has no way of knowing what your password is, the data becomes unrecoverable.

Sorry I can't give you better news.

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Chosen Solution

If the account password was changed without the recovery keys, the data can't be recovered unfortunately. This has to do with how your data is encrypted. It's encrypted using the Firefox Account password. When the Firefox Account password is changed, it no longer matches the password needed to decrypt the data. Since the Firefox Account system has no way of knowing what your password is, the data becomes unrecoverable.

Sorry I can't give you better news.

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If you still have access to the Windows computer then it is much easier to transfer your personal data directly via a USB drive.

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.


You can copy specific files with Firefox closed to the current profile folder to transfer or recover personal data.


  • 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 (passwords) and key4.db (58+) or key3.db (57 and older) (decryption key) for Passwords saved in the Password Manager
    if you only have key3.db then make sure to remove an existing key4.db
  • cert9.db (58+) or cert8.db (57 and older) for (intermediate) certificates stored in the Certificate Manager
    if you only have cert8.db then make sure to remove an existing cert9.db
  • persdict.dat for words you added to the spelling 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)