Does borderless windowed add input lag compared to fullscreen?

Borderless windowed adds no input lag over exclusive fullscreen when Windows runs it in Independent Flip, and about one display refresh when it does not. The difference is not the menu option, it is the present mode Windows picks for the frame: in Independent Flip your frames go straight to the screen, and in a composed mode they wait for the Desktop Window Manager (DWM). At 240 Hz that refresh is 4.17 ms. A free tool tells you which mode you are in within a minute.

Why two answers circulate

"Fullscreen is always faster" was true for most of the history of Windows gaming. Windowed games copied each frame into a surface owned by the DWM, which then composed the desktop. Microsoft's DXGI flip model page describes that older "bitblt" path as an extra copy on every present, and its timeline shows the DWM waking "at the next vsync" to compose the frame, with the monitor showing the result on the vsync after. James Darpinian's latency notes put the cost bluntly: for every application running in a window, "DWM adds one whole frame of input latency".

"Borderless is the same now" is also true, under conditions. Microsoft's flip model guidance says flip model presents go "as far as making windowed mode effectively equivalent or better" than fullscreen exclusive. When a flip model window covers the screen with buffers that match it, Windows can skip composition entirely, let the DWM "go to sleep", and send the game's frames to the screen "with the same efficiency as fullscreen exclusive". Microsoft calls that Independent Flip.

Both camps are describing a real present mode. Which one you get depends on the game's graphics API, one Windows 11 setting, and what else is on the screen.

What the compositor costs, in milliseconds

The DWM composes on the vsync, so its frame is a display refresh. The cost shrinks as refresh rate rises and matters most on a 60 or 144 Hz panel.

At 144 Hz that is more than the whole difference between a 144 Hz and a 240 Hz monitor's frame time, which is why it belongs on the same list as the render queue rather than in the noise.

Read the present mode, not the menu

Intel's PresentMon reports the mode Windows used for every frame. The names it prints, and what its README says each one means:

To check, run PresentMon --process_name yourgame.exe during a match and read the PresentMode column. "Hardware" means the compositor is bypassed; "Composed" means you are paying it. For a number for your own chain, add a latency measurement.

What to change, by situation

The Windows 11 setting is under Settings, System, Display, Graphics, as Optimizations for windowed games. Microsoft Support says it moves DirectX 10 and 11 games in windowed and borderless modes from blt-model to flip-model presentation, "reducing frame latency" and enabling Auto HDR and variable refresh rate; restart the game after switching it. It switches itself on if Auto HDR is on, and can be turned off per game under custom options for apps. The DirectX team's announcement adds that DirectX 12 games "already take advantage of the new presentation mode".

Exclusive fullscreen is not always what it says either. Microsoft's fullscreen optimizations post explains that Windows "takes full screen exclusive games and runs them instead in a highly optimized borderless windowed format", and reports from telemetry that performance is "on average, as good or better than FSE". If PresentMon shows a composed mode in fullscreen, tick "Disable fullscreen optimizations" in the game executable's Properties, Compatibility tab, and test again. If it already shows a Hardware mode, leave it alone.

Stretched resolutions and overlays

Independent Flip does not require native resolution. Microsoft lists "DirectFlip with panel fitters": the window covers the screen and the game's buffers are within a hardware-dependent scaling factor of it, "for example, 0.25x to 4x", with the GPU's scanout hardware doing the scaling. A 4:3 stretched render in a borderless window can therefore still bypass the compositor. Microsoft notes one side effect: with panel fitters "it's possible for the cursor to suffer stretching".

Overlays are the other trap. When something draws on top of the game, Microsoft says the DWM can drop back to composed mode, or keep Independent Flip with a multi-plane overlay (MPO). Darpinian's 2022 notes list MPO support as Intel GPUs and Nvidia RTX 20 series or newer.

Where this stops applying

Everything here is Windows and DirectX, because that is what Microsoft's documentation covers. We have not sourced how Vulkan or OpenGL games are presented, so this page makes no claim for them beyond what PresentMon shows you. The one-refresh figure is the compositor's own cost and says nothing about the render queue, usually the larger term in the click-to-photon chain. And no table predicts a specific game's mode: a patch, a driver or an overlay can change it, so check again after any of them.