日本語環境では上手く動きません。IMEで変換候補決定時にEnterすると、入力が終了して適用されてしまいます。
IMEを使用する他の言語でも同様と思われます。

Unfortunately doesn't rename across the domain, or if you reload the page. Would recommend Tab Mix instead.

Looked good at first - simple and easy. But my saved names aren't persisting - they're reverting back to defaults.

I compared this addon with "Tab ReTitle" (https://addons.mozilla.org/de/firefox/addon/tab-retitle/?utm_source=addons.mozilla.org&utm_medium=referral&utm_content=search).

This one is quite limited. The custom name is gone even if a small part of the URL changes (for example: you open a price comparison site and add another product). This way, it is not useful for me. The other addon "Tab ReTitle" has several options how persistent a new name should be.

Works fine for static pages, but does not override pages changing their own titles.

It lacks a crucial feature: I am going to the same URL but in different containers, and I need to be able to (permanently) rename them differently.
Also, is there no support site?

Immediately I noticed it doesn't keep the tab name when using it. I'm using Firefox Browser 73.0.1 (64-bit)

This is no longer working properly for me - the tab title disappears once the tab is closed. So my bookmarks revert to their original tab titles. Hope this can be fixed as it was really helpful before!

Didn't work for my use case. :( The reason I wanted this extension is to make my Tumbr tab stay named "Tumblr" instead of changing to "(3) Tumblr" etc every time I had some unread posts. Sadly this doesn't seem to work: initially the "(3) Tumblr" did become "Tumblr" when I renamed it, but then a few minutes later it became "(2) Tumblr" again after some unread posts appeared. Could you please make the tab-renaming persistent even if the website tries to change the tab title?