I have 1 profile on 4 laptops plus 1 Macbook Pro(wife is the Apple head). I'm now running 83 and 84 on Tumbleweed and whats good about it is that my BFF Sync now sees the different versions as different devices and I can now see my machine (Tumbleweed) in Sync. I can now share tabs between the browser versions like a backup

Operating System: openSUSE Tumbleweed 20201216 KDE Plasma Version: 5.20.4 KDE Frameworks Version: 5.77.0 Qt Version: 5.15.2 Kernel Version: 5.9.14-1-default OS Type: 64-bit Processors: 8 × Intel® Core™ i7-4810MQ CPU @ 2.80GHz Memory: 31.0 GiB of RAM Graphics Processor: Mesa DRI Intel® HD Graphics 4600

You can transfer the bookmarks directly by copying files via a removable USB stick. You can either use places.sqlite (bookmarks and history) or a JSON backup in the bookmarkbackups folder.

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.

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.

• Help -> Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-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 (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)

Keep it simple... just log into Firefox on the 2nd machine and watch everything come over. To get an idea how it will flow, just create another profile on the same machine and log into Firefox and you'll see what happens.

@cor-el: Thanks. I'm well aware (at least I hope so) that I can transfer files/data from one FF profile to another. I have been using bookmark backups to do it for years, but I have so many bookmarks that each syncronization takes quite some time now. (Edit: see below, I just did one)

@jonzn4SUSE: when you say that you log into Firefox I interpret it as you using FF sync, am I understanding correctly? How heavy is your FF workload though?

I ask this because last time I tried, mine was sinking Firefox Sync (sounds funny :D ) and I wasn't able to use it at all. As I mentioned there's >17K bookmarks (backup is 5MB) plus on average 150 open tabs and a rather heavy history too (profile is 450MB, places.sqlite is 20MB).

I wanted to have a more accurate feeling so I just imported the bookmarks backup inside my laptop: Firefox froze for a full 10 minutes on a reasonably fast machine (cpu is 8K passmark, 16GB of RAM and a 250GB SSD, it's a System76 Galago Ultra Pro, not the latest hardware but still very performing)

Cheers

Transferring bookmarks via Sync is done in rather small chunks (maybe 200 bookmarks) and with 15000 bookmarks you can expect to take this rather long time. If you have the possibility to transfer the bookmarks directly then there is no need to wait that long.

Of course, but doing so every time I update those bookmarks on either machine would be rather cumbersome and time consuming too!

But from this discussion I seem to have received an intuition and I would like to hear your opinion/s:

• What if I created a new profile on both machines, restored the old bookmark set in both of them and then sync through Firefox Sync?

Do you think the sync process could then manage? Both machines would have the same starting set, hopefully, and at that point chunks of 200 would be enough unless I spend many weeks without using one of the two PCs.

I'd lose the history and would have to manually pick the tabs I need and reopen them on one machine, but perhaps the long term hassle would come to an end....

Thanks and kind regards, Giampaolo

Transferring the bookmarks by copying the file(s) is only to avoid a lengthy initial Sync. One you have all the bookmarks then you should be able to use Sync for updating without problems.

In case of issues you can check about:sync-log via the location bar to see whether recent Sync logs are available.

Fair enough, I will give it a try then. Thanks!

A quick update & thank you: I did it!

It was quite a lengthy process that implied:

• Saving all my open tabs into bookmarks on my laptop,
• Exporting (i.e. backing up) bookmarks from the laptop into the classic JSON file
• Importing the updated bookmarks into my workstation. This one took literally hours (I am guessing between 2 and 3) even if the machine is an AMD FX-8350 processor based workstation equipped with 32G of ram
• Saving again all open tabs that required bookmarking into bookmarks and then backing them up on a newer version of the JSON
• Creating a fresh Firefox profile on the workstation and importing the JSON with the bookmarks (this time it required "only" 20 minutes)
• Creating a fresh Firefox profile on the laptop and importing there the JSON too (another half hour process)
• Logging into the FF account and syncing

On the first attempt to sync Firefox completely froze the laptop and I needed to kill it, but the day after it resumed syncing and apparently it completed. If Sync succeeds in keeping the two profiles up to date it will be a big progress from the old routine for me, so again: thank you all. You have been kind and very helpful.