As others have written, this extension has problems. The biggest are that while it might identify duplicates, it does not offer a way to select duplications for deletion. This might be fine if one had a few duplicates. It quite another thing if one has hundreds or more duplicates.

Second, the extension supposedly identifies broken links. However in spot checking some of these links, I find they are working.

Lastly, if one has thousands of bookmarks, this program will consume lots of memory. You mostly likely will get Firefox or even Windows to have problems.