See: *https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them *https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer *https://support.mozilla.org/en-US/kb/import-bookmarks-html-file ---- You may want to reset the password of the Sync account if you want to sync logins and possibly other data among other devices. A password reset will clear all data on the Sync server, so best is to disconnect all devices beforehand and reconnect one device at the time (start with the device that has the most recent bookmarks) and give it enough time for the initial sync to finish. Syncing bookmarks can take considerably time as this is done in small junks in the background. Make sure to backup the bookmarks so you can restore them in case of issues. You can possibly do the reset directly on the Firefox account page. *https://accounts.firefox.com/signin *https://accounts.firefox.com/settings