Counts only number of tabs of current browser-window.

I would like this if it worked - it's very simple and shows simply one number on icon. For most likely totally useless, but I'd like to see it. But it only shows the number when I'm on "new tab" page - when I go to another page or switch to another tab, the number disappears. I would consider it useful if I could just see how many tabs are open by quick glance, but instead I would need to:
1) open new tab
2) look at tab count
3) close the tab
...
4 (some times): switch back to the tab you were in originally.

So no, not worth it.

No Preferences you can set.

Color options are ok (black text on blue/teal background) but could have more contrast.

Font size is kinda small IMO.

All in all, if all you want is a tab count then it will work but if you want configuration, better to keep looking.

開発者の方が書かれている『Tab Counter』から乗り換えました（もう旧アドオン消滅したんですねぇ/2020年）。Quantum になってから結構経ちましたが本当に感謝。
タブ300とかよくわからないレベルのタブ数になっていて今は900…101！と桁数オーバーしてしまいました……減らすぞ…と目標にしております…が減りませんねぇ（これを書いているとき981タブ）。よく再起動でメモリリセットしてます…( about:profiles )。
他レビューにありますが、タブ一覧は新規タブを開く「＋」の横に13タブ目から表示される「ｖ」から見れますね。

Works well for me (FF 63.0.1 32 bits), simple, no options, sits next to the URL bar. The badge is blue/green, with black letters, discretion ok. On some site, like on this one, sometimes take a little delay to update page number, but short.

No aesthetic options.

very bad. Causes firefox to hang when there are man many tabs opened. Spikes the memory usage as well. Please FIX it.

Count Tabs is great! It does just what it's description said it would, and does it very smoothly! It helps me keep track of, and limit, tab over-population.

Perfectly to the point.

シンプルで良いです

デザインが好みです。クリックにタブ一覧の表示等の、
なにがしかのアクションを設定することが出来たら良いなと思います。

I always wondered how many tabs my main Firefox window had, and now I know: 535 tabs. I knew there were a lot, but maybe I should clean up. :-D And I have 6 more FF windows...

For 5 stars, make the icon respond to clicks and list all open windows with the count of tabs next to them and possibly a total count beneath. Clicking a window in this menu should bring forward the clicked window (if possible).

クリックしたらタブのリストがでてくるとよりよいと思います。