This addon does what it should, has lots of options, but most importantly, it allows you to define the deletion rules along with which bookmark folder to apply them on, which other extensions don't do. This allows you to delete duplicates in just about any way you wish.

For example, you can remove the duplicates only in one folder that you specify, or you can select the folders in which duplicate bookmarks will not be deleted, while deleting them everywhere else. Very useful.

Small, Unglorified... and, no non-sence... This app does exactly what it says it will do.. NO BOOKMARK DUPES... It saved me a complicated mess of 1Million bookmarks being compound doubled due to Chrome Sync and a Third Party Sync app just getting it plain wrong. No Chrome extensions could fix my mess. Other Firefox extensions, LOOKED good but expected me to click on each bookmark to delete (Ya Right). This is the ONLY one that did the job, and did the job Right, with just the right amount of control to get exactly what i wanted back. Thank You Martin!

Amazing addon. Solved my years of problem that storing too many duplicate bookmarks! Works perfectly.

Fantastic program. Had been manually trying to remove duplicates caused by Xmarks issues months ago. Installed Bookmark Dupes and not long after it had removed 11293 duplicates. Very easy to use. No problems encountered so far either.

Bravo, exactly what I needed. Removed 724 duplicate bookmarks and took a few mere minutes. Automatically pick oldest added duplicate worked for me.

After a Firefox account sync on a new machine, I was left with many duplicate bookmarks. This extension removed them, and then the empty folders they had been in, with just a few clicks. It took just a few moments. This was a great time saver.

Quickly handled 12,000 duplicate bookmarks caused by bugs in Xmarks

Highly recommended!

Probably the best extension to remove duplicates at present.

I had over 1322 duplicate bookmarks because of a syncornisation error and this simple addon did the job in less than a minute.
Simple design, easy to use and a top recommendation !

really helpful

Awesome and fast UI for selecting duplicates in one go, and just one click to delete... Really appreciate that only bookmark editing permissions were required! Suggested improvement: deletion process is slow with lots of disk usage (read/writes). Perhaps add option to process the deletion entirely in RAM?