You can install the About Sync extension to check what data is stored on the Sync server via the about:sync page provided by this extension.

• About Sync https://addons.mozilla.org/firefox/addon/about-sync/

Close and restart Firefox to access the about:sync page added by this extension (see the about:about page for possible about pages).

Thanks for the link, I installed the Extension. It shows a lot of information - surprisingly, information I thought I'd deleted too.. However, I'm still really confused about what is happening. I have a device that I'm completely happy with the passwords stored on - and I sync it. I have other devices that are also synced - but they show other accounts & passwords that I have deleted - why?

I just took the drastic step of signing out of the FF account on one of the Android devices and did a reset of the App data - completely wiped it. All bookmarks and passwords were gone. I then added it again and synced - and all the superfluous accounts & passwords came back! For clarity, these details are not on the PC I consider the 'master' that I want to be synced. Obviously, if the sync was working properly, there is no real 'master' as such - but my frustrations are that I spent time on one device tidying everything up and some changes have been made but other haven't.. In the Extension, there is a 'Validation' section where it shows 93 problems of 'server records appear on the server but not on the client.' I think these are the entries I spent time deleting from the PC - yet it seems to think they should appear? Is there away to remove whatever is held in the cloud and re-sync it all? Crazy that a 3 supposedly synced devices are different. EDIT: I've done some testing - info I delete from the PC is not deleted from any other devices - it's added to the 'server records appear on the server but not on the client' section and remains on the other devices, even after syncing them. Online info suggests that signing out of a device should ask to delete synced info but the option doesn't appear. Maybe I need to delete my account completely while signed out - that would surely delete everything. I can then re-create it using the same email address? Ridiculous if so :(

There is no master when it comes to Sync, all devices are equal and data from all devices is uploaded to the Sync server and this data is merged to other connected devices. You need to clear data on the Sync server and possibly on other devices and then first connect the 'master' device and give it enough time for the initial sync to finish properly and then (re)connect other devices one at the time.

Thanks, I know there's no master when it comes to sync, I've literally said as much above - yet, when I delete things from my main PC and sync both it and others, those deletions are not replicated on other devices - again, as I've said above. You say I 'need to clear data on the Sync server and possibly on other devices' - this I know and have asked many times now how I do this. As you advise, can you tell me how I 'clear data on the Sync server'? Equally, I've done it on other devices too by literally clearing all settings so no details remained. Yet, adding them again to my FF account added unwanted details that they previously had but are not on my PC. My thoughts are that clearly there is some corruption on the server sync profile. I have a PC with all the settings, bookmarks, passwords etc. that are good. Details on other, supposedly synced devices are not. My question is how do I resolve this? The extension I was advised to install onto my PC sees 'server records appear on the server but not on the client' - which must be my PC. When I delete passwords from this PC, the number of records increases and they are not deleted from the 'synced' devices.

You should be able to do this within the About Sync extension and also by resetting the password of the Sync account.

• https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information

Thanks, I found a 'Wipe Passwords' option in the extension's Engine Actions section. I do it and sure enough, all passwords are removed from the server as far as I can see. In fact, the whole Passwords section disappears. However, is there some cache or other information held in FF - as when I then Sync the PC I wish to have as the starting point, it adds them all - but lists 'deleted' ones too. See attached for how it looks immediately after a Sync. In the Record Editor (server) section they appear to have an entry with (tombstone) after them. However, despite the tidy up, if I delete an entry from the Passwords screen and then sync, it is not deleted from other devices. The Validation tab then gets an entry (as mentioned above that 'server records appear on the server but not on the client.' If I change a password on the same PC, these changes are successfully synced.

Firefox keeps deleted logins saved in logins.json in the Firefox profile folder. Login data (username and password) is removed and only its GUID and some other meta data is kept, only a "deleted":true key/value pair is added.

OK, that's good to know, many thanks! Any idea why deletions aren't synced to the other devices but changes are? It looks like there's still no way to remove all passwords from Android FF and they either need to be deleted manually and individually (not really an option for around 400 accounts) or have the entire profile wiped (clear data). Is there a way to remove those deleted entries from the server/logins.json file - in case they're causing some issue? Ask FF to stop remembering them? Delete the logins.json (and backup) file? On PC, if I export to csv, delete all and then import the csv would it look identical to the user - no info at all is lost?