Is it safe?

What Tessellate does

To run several copies of one game at once, Tessellate does a few things on your PC. All of them are limited to the games you start from it.

• Gives each player their own game folder (a mirror of the install) so every copy can have its own saves and settings.
• Makes temporary config and registry edits a game needs (a window mode, a profile name). They are written down first and put back when the session ends, or the next time Tessellate starts if it crashed mid-game.
• Hooks controllers and keyboards with ProtoInput (a small, open-source MIT-licensed library) so each copy only hears its own player. It is injected only into the game copies Tessellate starts.
• Places and resizes the game windows so they tile the screen.

What it never does

• It collects no data about you and shows no ads. There is no account.
• It never touches a game you didn't start from it, and never injects into a running program you didn't pick.
• It doesn't crack, patch or pirate games. It plays copies you own.

The optional Steam emulator

Some games refuse to open twice under one Steam account. For those, Tessellate can use the Goldberg Steam emulator (downloaded separately, only when you ask). It is off by default, meant for games you own, and never used with a game that has anti-cheat: Tessellate looks for the common anti-cheat files and refuses. Don't use split-screen tricks in online games that forbid them.

Why Windows might warn you

Tessellate puts a controller hook into other programs, which is exactly what some malware does too, so Windows Defender or SmartScreen may be suspicious of a new download, or flag the hook. Nothing here is hidden: the behaviour is described on this page. If a warning appears, check that the file came from this site, then choose More info → Run anyway, or add an exclusion for the Tessellate folder in Windows Security. If you're unsure, don't run it.

Everything is reversible

Stopping a game restores the files and settings Tessellate changed. Tessellate plays from per-player mirrors, so your original game folder is left as it was.

Report a problem

Found a security problem? Please write to security@tessellate.games before sharing it publicly. We'll answer as soon as we can.