The best free alternative to Overwatch is Paladins. If that doesn't suit you, our users have ranked more than 25 alternatives to Overwatch and many of them is free so hopefully you can find a suitable replacement. Other interesting free alternatives to Overwatch are Team Fortress 2 (Freemium), Unreal Tournament (Free, Open Source), Xonotic (Free, Open Source) and Cube 2: Sauerbraten (Free, Open Source).
A truly free and open source multiplayer shooter, no strings attached. Have casual deathmatch matches on various scenarios. Build your own levels with the ingame editor and assets that come with the game, or just play around and use it as a sandbox.
Ironsight is a free to play 1st person shooter which places you in the footsteps of a warrior fighting for control of the last natural resources on Earth. It is the year 2025, and two powerful rival factions jockey for ultimate control.
Across any terrain, with any weapon, against any opponent—the war must go on! Test your prowess with modern first-person shooter action in intense warzones ranging from labyrinthine urban locales to dusty desert battlefields.