Sidebery

The browser tab layout has been mostly untouched over the years: it's the usual horizontal style, plain and simple. People have attuned to using them, so the change to a vertical layout might make things uncomfortable for some.

Still, if you were looking to change things around and adopt a vertical, tree-based layout for your tabs, Sidebery is the extension to use. It's worth noting that it's only available for Firefox.

All that users have to do is add the extension to their browser, and it'll automatically install. Clicking its icon will then open up a sidebar where the tabs are to be stored. By default, it will open on the right side of the screen, but you can move it to the left in the settings if that's your preference.

New tabs will be shown in the sidebar, and from there, users can manipulate them to their liking. You can put certain pages in containers, divide them by panels, and so forth. The panels come in especially handy when you're working on two separate things at once and don't want them to intermingle: this keeps them separated, all while allowing users to be more organized in their browsing.

To further that, grouping is also possible. Have multiple tabs of a site opened? Group them up, so you won't scatter them about.

Navigating to the Settings menu brings up a load of options to configure. The sidebar's behavior can be changed to best fit your preferences: use the native context menu, choose how you interact with the tabs, create containers, and many other such particularities. Users can customize the style of the sidebar by modifying its color theme.

The extension also has the capability to sync your settings, so you can carry them over whenever you require.

For an extension that is supposed to offer users a sidebar in their browser, Sidebery truly takes it a notch above with the amount of customization and features it offers to its users.