LeanFPS

About LeanFPS

LeanFPS is a game optimizer for Windows 10 and 11 that automatically detects the game you launch and applies performance tweaks tailored to its genre. The app measures your frame rate and 1% lows each session, allowing you to see if optimizations actually help on your specific PC.

The free version includes game detection, FPS measurement, and core system tweaks. LeanFPS Pro adds game-time tweaks and per-genre profiles, with the first three games receiving full Pro features for trial. Pro is a one-time payment of $19 for early adopters (later $29), with no subscription required.

LeanFPS prioritizes safety and reversibility. It never touches security settings like Microsoft Defender, Memory Integrity, the firewall, or Windows Update. Every change is recorded and can be individually undone, or all changes can be reverted at once. The app runs lightweight at about 6.5 MB installed.

• game optimizer
• performance measurement
• windows
• system tweaks
• per-genre profiles
• fps optimization
• gaming performance

FAQ

Is LeanFPS safe for VALORANT, CS2 and other anti-cheat games?

LeanFPS never injects into a game, never reads or writes game memory or files, and shows no overlay. It changes Windows settings and process priority from outside the game. When an anti-cheat blocks priority changes on the running game, LeanFPS uses the Windows launch priority setting instead, which applies the next time the game starts.

Can I undo everything?

Yes. Before each change LeanFPS saves the real previous value, not a guessed Windows default. You can turn off any tweak on its own, press Restore all, or run leanfps.exe --restore-all. Changes made only while a game runs are undone when the game exits, and after a crash they are undone the next time LeanFPS starts.

Is LeanFPS Pro a subscription?

No. LeanFPS Pro is a single payment: $19 at the early-bird price, $29 later. Updates to the app are included; there is no monthly fee and no renewal.

How many PCs can I use LeanFPS Pro on?

Up to three PCs per key. To move Pro to a new PC, click Remove Pro from this PC in the old one, or remove it on the license page with a link we email you.

Does a game optimizer actually increase FPS?

Sometimes, and usually by a few percent rather than a lot. The biggest FPS gains still come from in-game settings and upscaling. What a game optimizer can fix is the PC getting in the way: power saving between frames, background apps taking CPU time, Windows moving the game to efficiency cores. LeanFPS measures your average FPS and 1% lows each session so you can see whether it helped on your PC.