Sarra.io is a very similar game to Tankster.io. The game was originally created by the creator and developer of tankster.io, MTS, it is currently developed by the staff team of tankster.io, getting updated daily with brand new features, tanks and more. In Sarra.io, there are exclusive ranks for specific people, the Beta Testers, the Senior Testers (which are now beta testers) and the Developers (those who have code access).
Sarra.io was originally released on June 27th 2021 and it was private and only accessible by those who had code access. Some months later, the ranks Beta Tester, Senior Tester, Server Access and Code Access were created, and the game became public, however it could only be accessed with a token or a password unless there was an event where members or non-testers from sarra could join without a token and try the new tanks and features. On August, the game was officially released to the public, tokens could still be used but those who did not have a token could enter their name normally and play, just like in Tankster.io. The Senior Tester rank has been deleted.