The feature has recently been added to the Canary build
Microsoft Edge is a continuously evolving browser, and one of the biggest new features coming to the app is support for vertical tabs. If you haven’t used Vivaldi already, you really should, as it’s one of the few apps right now coming with vertical tabs and it should help you figure out why this is such a cool feature for everybody. Microsoft too knows that vertical tabs can make the browsing experience overall a lot more convenient, especially on large wide screens, so the company is currently offering this feature in the testing builds of Edge, with the goal of bringing it to the stable channel at some point in the future.
