Fullscreen Optimizations On Or Off Link Jun 2026

Fullscreen Optimizations (introduced in Windows 10) tries to give you the performance of exclusive fullscreen while keeping the benefits of borderless windowed (fast alt-tabbing, overlays). It basically runs your “fullscreen” game in an optimized borderless mode.

Sometimes, developers implement Fullscreen Optimizations incorrectly. You might see a situation where the game claims to be fullscreen, but your mouse cursor drifts onto a second monitor, or the resolution doesn't scale correctly. In these specific bug cases, disabling FSO is the fix. fullscreen optimizations on or off

Should you blindly toggle the setting? No. You should test it. Here is how to check if your specific game benefits from disabling FSO: Fullscreen Optimizations (introduced in Windows 10) tries to

When FSO is on, the game is technically running through the Desktop Window Manager. Even though Microsoft has optimized this process heavily, it adds a layer of processing between your GPU and the display. You might see a situation where the game

Designed to give "Borderless Windowed" mode the same performance as "Exclusive Fullscreen."

For the average player, this is negligible. However, for high-level competitive play (think Counter-Strike 2 , Valorant , or Overwatch at 300+ FPS), every millisecond counts. Players turn FSO to force the game back into "Exclusive Fullscreen" mode.

Here’s the short answer: