Pick Tabula if
Your work spans several sites and you want them side by side on one canvas instead of in tabs.
The catch. It runs on macOS only, it is closed source, and it is newer than everything else here.

Tabula is best for seeing many sites at once. Vivaldi is best for customising everything.
Your work spans several sites and you want them side by side on one canvas instead of in tabs.
The catch. It runs on macOS only, it is closed source, and it is newer than everything else here.
You want tabs on any side, tab stacks, tiling and a setting for nearly everything.
The catch. The number of options takes time to learn, and its interface is not open source.
| Tabula | Vivaldi | |
|---|---|---|
| Engine | Chromium | Chromium |
| Vertical tabs | On by default | Yes, tabs on any side |
| Sites on screen at once | As many as you arrange, on a canvas | Several, with Tab Tiling |
| Separate workspaces | Zones — two free, unlimited on the paid plan | Workspaces and profiles |
| Ad and tracker blocking | Built in, ads and trackers | Built in, ads and trackers |
| Extensions | Chrome Web Store | Chrome Web Store |
| Platforms | macOS | macOS, Windows, Linux, iPhone, Android |
| Open source | No | Partly — the interface is closed |
| Price | Free; $9.99/month for unlimited zones | Free |
| Development | Active | Active |
Neither wins everywhere. Tabula is best for seeing many sites at once; Vivaldi is best for customising everything. Pick Tabula if your work spans several sites and you want them side by side on one canvas instead of in tabs. Pick Vivaldi if you want tabs on any side, tab stacks, tiling and a setting for nearly everything.
They block the same way: built in, ads and trackers.
Both install extensions from the Chrome Web Store.
Tabula: macOS. Vivaldi: macOS, Windows, Linux, iPhone, Android.
Tabula: Free; $9.99/month for unlimited zones. Vivaldi: Free.