Many years ago they had an offical extension called “Tab Center”, it had been in “labs” for some time. When it finished testing (it worked well), Mozilla decided to drop it instead of deploying it in Firefox. It wasn’t even in low priority.
It took them many years and they finally implemented vertical tabs in 2024.
That was the move to Firefox 3.0, wasn’t it? Back when major Firefox releases were actually major and not just minor changes to a few tertiary features.
I’m pretty sure that upgrade killed more addons than every update since then combined. It took years for some of them to return.
Sorry for AI but I couldn’t find it by just googling:
Yes, Firefox did have an in-house developed “Tab Center” — it was an experimental feature created by Mozilla as part of their Test Pilot programme around 2016–2017.
🧪 Mozilla’s Original “Tab Center”
Name: Tab Center
Status: Experimental Test Pilot feature (now discontinued)
Timeframe: Circa 2016–2017
Purpose: To explore the usability of vertical tabs on the left side of the browser, instead of the traditional horizontal layout.
🔍 Key Features
Displayed open tabs vertically in a sidebar.
Showed a more spacious, scrollable list of tabs.
Included favicons and tab titles — easier to manage lots of tabs.
Supported mouse gestures like tab pinning and closing.
Looked and felt very similar to Edge’s modern vertical tabs.
Pretty accurate except for “we must focus on the browser”, I’ve never seen/heard them doing that.
I still remember when they cancelled vertical tabs after successful testing.
From their announcement about ending Pocket and FakeSpot:
Far be it from me to say they act upon these statements, but I do see them made.
Edit: yay more AI
They did? I still have it enabled and it works. If I get an update that removes this, mozilla can go shit themselves
Many years ago they had an offical extension called “Tab Center”, it had been in “labs” for some time. When it finished testing (it worked well), Mozilla decided to drop it instead of deploying it in Firefox. It wasn’t even in low priority.
It took them many years and they finally implemented vertical tabs in 2024.
I remember using an extension for that in like 2008 or something.
And I remember them disabling the features that extension required to function.
That was the move to Firefox 3.0, wasn’t it? Back when major Firefox releases were actually major and not just minor changes to a few tertiary features.
I’m pretty sure that upgrade killed more addons than every update since then combined. It took years for some of them to return.
When was that? I only ask because Firefox has vertical tabs now.
Sorry for AI but I couldn’t find it by just googling:
Yes, Firefox did have an in-house developed “Tab Center” — it was an experimental feature created by Mozilla as part of their Test Pilot programme around 2016–2017.
🧪 Mozilla’s Original “Tab Center” Name: Tab Center
Status: Experimental Test Pilot feature (now discontinued)
Timeframe: Circa 2016–2017
Purpose: To explore the usability of vertical tabs on the left side of the browser, instead of the traditional horizontal layout.
🔍 Key Features Displayed open tabs vertically in a sidebar.
Showed a more spacious, scrollable list of tabs.
Included favicons and tab titles — easier to manage lots of tabs.
Supported mouse gestures like tab pinning and closing.
Looked and felt very similar to Edge’s modern vertical tabs.
https://duckduckgo.com/?q=Mozilla+test+pilot+tab+center
Ah TIL! I think it was finally added as of version 136, fairly recently.