Hi, Not sure why that would be happening. Please do this always and again after if it fixes the issue :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Inside Firefox open Help > Troubleshooting Information scroll down that internal page to Places Database and see the Verify Integrity button. Use that to fix the Places database file in your Firefox Profile folder.

Restart Firefox and see if that fixed the duplicates problem.

Please let us know if this solved your issue or if need further assistance.

1. Were you using Sync when that duplication occurred? And is a mobile / smart phone version of Firefox being used with that Sync account? If Sync is involved the corruption can be spread thru Sync and affect all devices.

2. Open up Help > Troubleshooting Information in Firefox and scroll down to Places Database and use the Verify Integrity button. Let that process run until you get the statistics for the repair procedure. Then see if that corrects the duplicate bookmarks.

Thanks to both of you!

Unfortunately, it did not work. I did it twice to the same results.

BUT - I looked at my folders more closely, and it appears the second set is an older version of the bookmarks file. There are numerous missing from various folders.

I'm certain I did not import any bookmarks. I export them periodically as a backup, but I've never had the need to import.

Is there any way I can edit exported bookmarks and get rid of that second set and them import the new list?

Hi, ya sorry if not clear it was to fix the issue and not to get rid of the duplicates.

To get rid of the duplicates you can open bookmarks in about 4 different ways so each would have to be hand edited by Right Click Delete or Drag all the Duplicates to a New Folder then Delete the Folder or keep them.

Yes you could export them but : If you are familiar with working with HTML links and see how the structure of the HTML of the Bookmarks is laid out, then any Web Editor will work as long as they do not add any code to the HTML page.

I would think as much as exporting is workable editing within Firefox Bookmarks would be much easier and more visual than looking at code.

As to how that happened might be that you had a prior Profile and Firefox Updated and the Profiles where merged. Or if as Fred asked if you were using Firefox Sync which is not meant for backup purposes but to share data/Profile between devices.

Just remember to do the 2 always in my 1st post. In case it happens again. Plus should do it regularly if you change your bookmarks often or use history.

Please let us know if this solved your issue or if need further assistance.

Thank you! I suspected I might have to get rid of them manually. I looked more closely, and it does appear the second set is smaller than the first and that the second set is an older version. I checked several folders, plus the tool bar folder, and they are different.

I'm not that good at html editing, so I'll just leave that alone :)

I do not use Firefox Sync, and sorry for failing to mention it.

I'm not able to work on it today, but will definitely get back to you with any resolution I come up with.