Works really well. You can configure it to ignore certain parts of the URL like after the search (?) part or hash (#) part of the URL as some sites will generate duplicate tabs with these parts different.

Fonctionnement hasardeux .

Works great. I really like the "Filters" options - without them the extension would be pretty much useless to me.

Absolutely beautiful. Exactly what I wanted. Automatically closing older duplicate tabs when a new duplicate is opened should be a stock option in firefox.

Simple, yet effective.

Excellent.

Drawback: the add-on seems to have been abandoned 4 years ago, as seen on Github:
https://github.com/Peuj/duplicate-tabs-closer

But I find a bug:
Whatever your choice in "Priority" parameter in the Options, the add-on always keeps the oldest visited tab. This parameter seems to not work at all.

And I also have two little requests:
- First one: it would be nice not to include the tabs "New tab" in the list.
- And second one: it would be nice to disregard (ignore) a final "/".

Both requests could have their checkbox in the Option page (with On by default).

But I don't know what to think, given that the developments seem to have been abandoned 4 years ago.

Write about my experience with this add-on? I wasted hours trying to figure out why I could have only one tab per domain. It didn't matter if the url was completely different. Utter POS because the PEUJ who designed it doesn't even know the meaning of "duplicate". IT MEANS "EXACTLY THE SAME", got that? Read again.

big productivity QoL for disorganized compulsive browsers (user)

Seems to work fine BUT ONLY IN ONE WINDOW ... I uses several windows and there are "no duplicates" found by this (and other) tab deduplication extension ...

Because of some somehow gone/lossed tabs I opened a saved session so I had to get rid of duplicated tabs.

Najlepszy! Szkoda, że brak języka polskiego.