LeanFPS is a Windows 10/11 x64 game optimizer for PC gamers. It detects running games, applies per-game and per-genre Windows settings, measures average FPS and low-percentile frame rates through Windows event tracing, and records sessions. Changes are restored when the game closes, and a Restore all option is available.
The publisher lists a 5.9 MB installer and 6.5 MB installed size. A free core edition is available, and optional Pro currently costs US$19 once. Its optimization list excludes disabling Defender, Memory Integrity, the firewall and Windows Update. Results vary by PC and game.
The product addresses a practical problem for PC gamers: manual Windows tweaks can be difficult to track, measure and reverse. LeanFPS brings game-specific settings, FPS measurement, session history and undo into a small Windows app, so users can judge changes on their own hardware.