Vertical space is still at a premium because most laptops use the obnoxious 16:9 aspect ratio. That’s why I keep my tabs on the right in Vivaldi.

Not to mention most websites love to waste vertical space. Navbars keep getting thicker, designers insist on having top bars even when the navigation is in the sidebar and the bottom is eaten up by cookie banners and chat/feedback popups.

I’m guessing the problem there is that mobile is far more unforgiving on horizontal space than laptops are on vertical space, so anybody building a webpage to target both ends up in the regime you’re talking about.

Good point. I suspect websites that start out as a Photoshop mock-up rather than a HTML5 prototype are more susceptible to this.

I've tried that, but you haven't lived until you've tried Tree Style Tabs in Firefox.

I like tree-style tabs, and I use it when working on projects, but I find that it is a long, long way from what it could be, which is probably a direct result of the lack of competition

the settings UI is absolutely awful;

depending on which appearance you choose, it either looks ugly or blurs together;

it frequently has visual glitches;

could certainly be more customisable appearance and shortcut-wise;

doesn’t allow you to have a title or marker as the top level tab;

as far as I can tell doesn’t let you save a session of tabs;

has an unpleasant glitch where if you drop a tab in the wrong place it’ll disappear behind the current window and never be reachable;

the new tab behaviour irritates me;

and probably a few more complaints that I’d have to actually open it up to remember

Sideberry is a worthy competitor : https://addons.mozilla.org/en-US/firefox/addon/sidebery/

I might try it next week, but if you'd mention Sideberry's advantages over TST that would be great.

Sideberry lets you turn off the "tree" feature and just have the vertical tabs.

The whole point of vertical tabs is so you have enough characters visible to tell what the tab is. Tab trees waste this precious space.

Sideberry is more complete out of the box. TST is more flexible for low level tinkering. That's what I read somewhere for TST, I use Sideberry.

As far as I can tell, Firefox, Edge and Vivaldi that are the only browsers with some way to get vertical tabs.

I don't know much about Vivaldi. Can you tell me what its monetization model is? Does it strip the google crap out of chromium?

Vivaldi was started by Jon von Tetzchner, the founder of Opera, and is meant to be a power-user’s browser with an emphasis on customizability and keyboard shortcuts, along with a range of unique features.

They do strip Google crud like FLoC, don’t pander to crypto scams and are employee-owned, you can check out their statements on Vivaldi.com. The only valid reason not to consider them would be that they are not open-source.

And that's why Tab Center Reborn (formerly Tab Center Redux) FF extension came to live, while vertical space is scarce on modern monitors horizontal is ample normally.

Ironically, Chrome still wastes slightly more vertical space than an appropriately configured Internet Explorer did.

> Vertical screen space was very precious when Chrome came out. I remember their first feature over Firefox was moving tabs into the title bar and removing the menu bar, bookmark bar and bottom status bar, so saving about four bars of space for page contents.

Was it really? When Netscape Navigator came out, 640x480 was probably the most common resolution. It used significantly more vertical space than Chrome has ever done. What happened between then and the release of chrome to make vertical space more precious?

Desktop computers have had very abundant screen-space for a long time.

> moving tabs into the title bar

Of all of the terrible UI elements that have become fashionable, this is probably the one I hate the most.