Sync will copy everything selected.

Use with Extreme Caution;

Bookmark Duplicate Cleaner {web link} Scans for bookmark duplicates and allows you to delete them

Bookmarks Checker - check for bad links {web link} Check favorites for broken or bad links. It checks for bad links and displays a report if it finds something. Check for 404 links, timeout links.

First a question. Are you running either Firefox for Android or Firefox for iOS on that Sync account?

No, all existing bookmarks on all devices connected to a Sync account are supposed to be merged without duplicates being created en masse.

Sorry, there are no "copies" of bookmarks; there is one set is on the Sync server to be merged with all the connected devices. When bookmarks data becomes corrupted, that corruption is spread to all the connected devices.

No, Sync is designed to be 'connected' all the time on all devices. Upon launch Firefox looks to the Sync server for changes since that last time that particular Firefox installation was used, and update that device as necessary. Plus as changes are made to the device you are using, those changes get sent to the Sync server, basically in "real time" until Firefox "sees" a massive number of changes being made in a short period of time [like when the user is rearranging a large number of bookmarks and/or folders of bookmarks]; then Firefox will "save" the changes and send them to Sync in batches.

Yes, more documentation is needed for Sync. I have tried a few times to get something going in that regard in the Contributors fora here, and the best response that I have gotten was telling me to write the KB articles myself and they will be reviewed. Sorry, but "I don't do KB articles" - one-on-one direct user support is my contribution here.

And as far as a Sync KB article goes - I was documenting the original Weave add-on, as Sync was known as it was being developed for the Firefox 3.x versions, and in Dec 2010 there was a massive changes made in the lead-up to Firefox 4.0 Release, with Sync built-in. Those changes made the documentation I was working on virtually useless; half of what I had done would have needed to be re-done. And since the Mozilla developers decided to not provide backward compatibility with the Weave extension (and the Firefox 3.6 version which was kept updated for a whole year after Firefox 4.0 was released) - that killed my ability to use Sync with my EeePC Netbook which couldn't handle Firefox 4.0.

Now as far as fixing what's messed up ....

If you are using Mobile Firefox (for Android or iOS), IMO that is were that corruption of your bookmarks in Sync probably started.

My advice is to

1. Disconnect from Sync on all devices;
2. change your Firefox Account / Sync Password to clear your data from the Sync server;
3. and then run Places Maintenance on every device to fix the corruption on all devices that were connected to that Sync account.

Once all devices are fixed, connect one device to Sync and only 'sync' Bookmarks, Passwords, and maybe Preferences for the initial Sync processes. Definitely don't Sync Add-ons initially.

Then wait a good number of hours with Firefox open on that device before you Sync a 2nd device. Don't rush when adding additional devices and keep track of your bookmarks to make sure they all 'sync' properly, and the the corruption doesn't begin again. And if corruption does happen again don't connect any more devices, it won't fix itself. Overall, be patient when connection the 2nd and subsequent devices; depending upon 'load' on the Sync server Sync seems to work in bursts of data transfer and it may take some time for all data to be sent to the 2nd and subsequent devices during certain time periods throughout the day.

Also, you may want to check Firefox Accounts Services Status - https://status.services.mozilla.com/ - before connecting an additional device to Sync. There were problems with the Sync server / FxA between April 3rd and April 9th, but that appears to be solved now.

It may be best to use the bookmark checkers I spoke of at https://support.mozilla.org/en-US/questions/1118719#answer-866903 on your primary device. Then, before using sync, remove the bookmarks from the other devices. This should leave you with only the primary's bookmarks.

Note: Create backups before using sync to protect your data.

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

OPIE {web link} Import/Export extension preferences

Thanks for the replies. I will back up my bookmarks, delete everything and start again from scratch. One machine per day.

By the way, I have one Windows machine and 4 Red Hat Linux machines.

I am running Firefox bookmarks for/on Windows

I tried your suggestion to disconnect Sync and then ran . . . Places Maintenance. The results were "Initial Database Size 20,480 kb" and "Final Database Size 20,480 kb" In other words none of the duplicate bookmarks duplicates were cleaned up. How about this - on the secondary computer I can go to Bookmarks: Show all Bookmarks: Organize: and delete all Bookmarks. Then I can go to the Primary computer Disconnect Sync, then go to Bookmarks: Show all Bookmarks: Organize: and delete only the duplicate Bookmark Lists.. Then on the Primary Computer, sign onto Sync with a new password. This will create a new Cloud list of Bookmarks. Then I can Sync the secondary computer to the new Cloud list.

Do you see any problem with that??????

the-edmeister said

Now as far as fixing what's messed up .... If you are using Mobile Firefox (for Android or iOS), IMO that is were that corruption of your bookmarks in Sync probably started. My advice is to

1. Disconnect from Sync on all devices;
2. change your Firefox Account / Sync Password to clear your data from the Sync server;
3. and then run Places Maintenance on every device to fix the corruption on all devices that were connected to that Sync account.

Once all devices are fixed, connect one device to Sync and only 'sync' Bookmarks, Passwords, and maybe Preferences for the initial Sync processes. Definitely don't Sync Add-ons initially. Then wait a good number of hours with Firefox open on that device before you Sync a 2nd device. Don't rush when adding additional devices and keep track of your bookmarks to make sure they all 'sync' properly, and the the corruption doesn't begin again. And if corruption does happen again don't connect any more devices, it won't fix itself. Overall, be patient when connection the 2nd and subsequent devices; depending upon 'load' on the Sync server Sync seems to work in bursts of data transfer and it may take some time for all data to be sent to the 2nd and subsequent devices during certain time periods throughout the day. Also, you may want to check Firefox Accounts Services Status - https://status.services.mozilla.com/ - before connecting an additional device to Sync. There were problems with the Sync server / FxA between April 3rd and April 9th, but that appears to be solved now.

I am running Firefox bookmarks for/on Windows

I tried your suggestion to disconnect Sync and then ran . . . Places Maintenance. The results were "Initial Database Size 20,480 kb" and "Final Database Size 20,480 kb" In other words none of the duplicate bookmarks duplicates were cleaned up. How about this - on the secondary computer I can go to Bookmarks: Show all Bookmarks: Organize: and delete all Bookmarks. Then I can go to the Primary computer Disconnect Sync, then go to Bookmarks: Show all Bookmarks: Organize: and delete only the duplicate Bookmark Lists.. Then on the Primary Computer, sign onto Sync with a new password. This will create a new Cloud list of Bookmarks. Then I can Sync the secondary computer to the new Cloud list.

Do you see any problem with that??????

robsten@yahoo.com,

How about using the thread that you started yesterday about your duplicate bookmarks problem. https://support.mozilla.org/en-US/questions/1134676

I tried to get this to you but I could not. The Places Maint did not work. See below.

I am running Firefox bookmarks for/on Windows

I tried your suggestion to disconnect Sync and then ran . . . Places Maintenance. The results were "Initial Database Size 20,480 kb" and "Final Database Size 20,480 kb" In other words none of the duplicate bookmarks duplicates were cleaned up. How about this - on the secondary computer I can go to Bookmarks: Show all Bookmarks: Organize: and delete all Bookmarks. Then I can go to the Primary computer Disconnect Sync, then go to Bookmarks: Show all Bookmarks: Organize: and delete only the duplicate Bookmark Lists.. Then on the Primary Computer, sign onto Sync with a new password. This will create a new Cloud list of Bookmarks. Then I can Sync the secondary computer to the new Cloud list.

Do you see any problem with that??????

Yes, see if that works.