For competitive gaming, use exclusive fullscreen – it provides 1-5ms less input lag by bypassing the Windows compositor. For casual gaming with dual monitors or frequent alt-tabbing, use borderless windowed – the input lag difference is imperceptible for non-competitive play and the multitasking convenience is worth it. In 2026 with DX12 games, the FPS difference between the two modes is under 3% on most systems – the old “fullscreen is way faster” rule barely applies anymore. See our gaming PC fix guide for deeper context.
This guide explains what each mode actually does under the hood, when the performance gap matters, and the specific scenarios where each mode wins.
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Why Borderless Adds Input Lag (And Why DX12 Changed Things)
The input lag difference comes from the Desktop Window Manager (DWM) – Windows’ compositor that manages all windows, overlays, and desktop rendering.
DX11 Games: Fullscreen Is Noticeably Better
In DX11 exclusive fullscreen, the game bypasses DWM entirely. Frames go directly from GPU to display with no compositor involvement. This provides the lowest possible latency and the most FPS because the GPU is not sharing resources with the desktop.
In DX11 borderless windowed, DWM composites the game window alongside the desktop, taskbar, and other windows. Each frame passes through DWM’s composition pipeline, adding 1-5ms of latency and consuming 1-5% of GPU resources for the compositing work.
DX12 Games: The Gap Has Nearly Closed
DX12 (and Vulkan) changed the relationship between games and DWM. Modern DX12 games use a “flip model” presentation that integrates with DWM more efficiently. In many DX12 games, borderless windowed mode performs within 1% of fullscreen because the flip model bypasses most of DWM’s compositing overhead.
This means: For DX12 games (most 2024-2026 titles), the performance difference between fullscreen and borderless is negligible. For DX11 games (older titles, some current games that still use DX11), fullscreen still provides a measurable advantage.
Actual Input Lag Numbers
| Mode | DX11 Added Lag | DX12 Added Lag | FPS Impact |
|---|---|---|---|
| Exclusive Fullscreen | 0ms (baseline) | 0ms (baseline) | 0% (baseline) |
| Borderless Windowed | +3-8ms | +1-3ms | -1 to -5% (DX11), 0-1% (DX12) |
| Standard Windowed | +3-8ms | +1-3ms | Same as borderless + title bar space lost |
Context: Human reaction time averages 150-250ms. A 3ms difference between fullscreen and borderless is 1-2% of your total reaction chain. For casual gaming, you will never feel this difference. For competitive FPS at high level (Radiant/Global Elite), every millisecond in the input chain matters – use fullscreen.
G-Sync and FreeSync Behavior Per Mode
Adaptive sync behaves differently depending on your display mode and Windows version:
- Exclusive Fullscreen: G-Sync/FreeSync works perfectly. The game has exclusive display control, and adaptive sync matches the monitor refresh to GPU output with zero interference.
- Borderless Windowed (Windows 11): G-Sync/FreeSync works in borderless on Windows 11 if enabled for “windowed and full screen mode” in NVIDIA Control Panel. Windows 11 improved DWM to support VRR in windowed modes. The experience is close to fullscreen but not identical – minor frame pacing inconsistencies can occur.
- Borderless Windowed (Windows 10): G-Sync support in borderless was added late in Windows 10’s life. It works but is less reliable than on Windows 11. Some users report occasional flickering or stutter in borderless that does not occur in fullscreen.
NVIDIA Control Panel setting: Open NVIDIA Control Panel > Display > Set up G-SYNC > check “Enable for windowed and full screen mode” (instead of “full screen mode only”). This is required for G-Sync to work in borderless windowed mode.
Common Display Mode Issues and Fixes
Borderless Windowed Stuttering
If games stutter in borderless but not fullscreen, the Windows compositor (DWM) is causing frame pacing issues. Fixes:
- Enable Hardware-Accelerated GPU Scheduling: Settings > Display > Graphics > “Hardware-accelerated GPU scheduling” ON. This reduces DWM overhead on modern GPUs.
- Enable G-Sync/FreeSync for windowed mode: NVIDIA Control Panel > G-SYNC > “Enable for windowed and full screen mode.”
- Close video on second monitor: Twitch/YouTube playing on the second monitor while gaming in borderless causes stutter because DWM renders both simultaneously. Pause video during competitive matches.
- Update to Windows 11: Windows 11’s DWM handles borderless gaming better than Windows 10. If you are on Windows 10 and experience borderless stutter, this is a known limitation.
Mouse Cursor Leaving Game Screen (Borderless)
In borderless mode, your mouse can drift to the second monitor during gameplay. Most games lock the cursor when in borderless mode, but some do not. Fixes:
- In-game setting: Look for “Confine Cursor” or “Lock Mouse to Window” in the game’s settings.
- Dual Monitor Tools (free software): Locks cursor to the primary monitor with a hotkey toggle.
- CursorLock (free): Locks cursor to the focused window automatically.
Resolution Mismatch in Borderless
If a game’s resolution does not match your display’s native resolution, borderless mode renders at the game’s resolution and Windows scales it to fill the screen. This can look blurry compared to fullscreen, which handles resolution scaling on the GPU. Solution: always set the game to your monitor’s native resolution in borderless mode.
Windows “Fullscreen Optimizations” – Disable or Keep?
Windows has a feature called “Fullscreen Optimizations” that automatically converts exclusive fullscreen games to borderless windowed mode for “compatibility.” This defeats the purpose of choosing fullscreen for lower input lag.
How to Disable Fullscreen Optimizations
- Find the game’s .exe file (Steam: right-click game > Manage > Browse local files)
- Right-click the .exe > Properties
- Go to the Compatibility tab
- Check “Disable fullscreen optimizations”
- Click Apply
Should you disable it? For DX11 competitive games: yes, disable it to ensure true exclusive fullscreen. For DX12 games: it barely matters because DX12 borderless is nearly identical to fullscreen. When in doubt, disable it – there is no downside.
Decision Framework
Quick Decision
- Competitive FPS (ranked play): Exclusive Fullscreen. Disable fullscreen optimizations on the .exe. Every input lag reduction matters.
- Dual monitor setup: Borderless Windowed. Fullscreen blacks out the second monitor and traps your cursor. Borderless gives you full second-monitor access.
- Streaming: Borderless Windowed. You need to access OBS, stream chat, and alerts on the second screen. The 1-3ms lag difference is irrelevant for streaming.
- Single-player / casual: Borderless Windowed. The convenience of instant alt-tab and notification visibility outweighs imperceptible input lag.
- Older DX11 game with performance issues: Exclusive Fullscreen. DX11 borderless has a larger performance penalty. Fullscreen gives you the most FPS.
- Modern DX12 game: Either mode works. Performance is nearly identical. Choose based on whether you value lowest possible lag (fullscreen) or multitasking (borderless).
- Strategy / simulation games: Windowed or Borderless. Being able to see other apps alongside the game (wiki, guides, spreadsheets) is more valuable than minimal lag in non-twitch-reflex games.
Related: mouse guide, keyboard guide, GPU guide, monitor guide.
2026 update: Gaming hardware evolves quickly. For the latest recommendations across mice, keyboards, monitors, and more, browse our interactive tools and hardware databases which are updated regularly with new releases and price changes.
Frequently Asked Questions
Does borderless windowed reduce FPS?
In DX11 games: yes, by 1-5% compared to exclusive fullscreen. DWM compositing uses a small portion of GPU resources. In DX12 games: barely – 0-1% difference because DX12’s flip model integrates with DWM more efficiently. The FPS reduction in modern games is negligible for all but the most GPU-constrained systems. If you are already GPU-bottlenecked and every frame matters, fullscreen provides a small advantage.
Does fullscreen have less input lag than borderless?
Yes. Exclusive fullscreen bypasses the Windows compositor (DWM), eliminating 1-5ms of compositing latency in DX11 games and 1-3ms in DX12 games. This is measurable with tools like NVIDIA Reflex Analyzer but imperceptible to most players. Competitive FPS players who notice sub-5ms differences should use fullscreen. Casual players will not feel the difference.
Why does my game switch from fullscreen to borderless?
Windows “Fullscreen Optimizations” automatically converts exclusive fullscreen to borderless for compatibility and faster alt-tabbing. To prevent this: right-click the game’s .exe > Properties > Compatibility > check “Disable fullscreen optimizations.” Some games also have “Exclusive Fullscreen” as a separate option from regular “Fullscreen” in their settings – make sure you select the exclusive version.
Can I use G-Sync in borderless windowed mode?
Yes, on Windows 11 with NVIDIA GPUs. Enable it in NVIDIA Control Panel > Display > Set up G-SYNC > select “Enable for windowed and full screen mode.” Windows 10 also supports this but less reliably. FreeSync works in borderless on both Windows 10 and 11. If G-Sync does not seem to work in borderless, verify the Control Panel setting and restart the game.
Is windowed mode the same as borderless windowed?
No. Standard windowed mode runs the game in a resizable window with a title bar, borders, and window controls (minimize, maximize, close). Borderless windowed removes the borders and title bar and stretches the window to fill the entire screen – it looks like fullscreen but runs through the Windows compositor. Performance-wise they are identical; the difference is visual (borders vs no borders).
Should I use borderless for Fortnite/Valorant/CS2?
For ranked competitive play: use Exclusive Fullscreen for the lowest input lag. For casual play or if you have a dual monitor setup: Borderless Windowed is fine. Fortnite and CS2 are DX11 games where fullscreen provides a slightly larger advantage than in DX12 titles. Valorant detects fullscreen mode and performs identically in both modes due to its lightweight anti-cheat overlay.
Research Sources
- Walkthroughs: Fullscreen vs Borderless vs Windowed – Performance comparison data and FPS testing methodology
- Blur Busters: Input Lag in Windowed vs Fullscreen – Technical analysis of DWM compositing latency and frame presentation
- Microsoft DirectX Blog: Fullscreen Optimizations – Official documentation on Windows fullscreen optimizations and DX12 flip model
All Related Fix Guides
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- Speed Up
- Windows
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- Check FPS
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