Input Lag Test — How Fast Can You React?
The screen flashes green at a random moment — click as fast as you can. We measure the total round-trip time including display latency, input latency and your reaction speed. Track your best, worst and average across rounds.
What input lag really is (and why reaction tests are an estimate)
Input lag is the total time between a physical event (a key press, a mouse click, a sensor reading) and that event being reflected on the display. It is the sum of many small delays across the whole pipeline:
- Input device latency — mouse polling, keyboard scanning, USB transfer. Typically 1-8 ms.
- OS processing — the OS receives the input and forwards it to the application. Typically 1-5 ms.
- Game/application processing — the game samples the input, runs the simulation, and prepares a new frame. Typically 1-16 ms (one frame at 60 FPS).
- GPU rendering — the GPU renders the frame and prepares it for display. Typically 5-30 ms depending on settings.
- Display latency — the monitor receives the frame and displays it. Typically 1-30 ms depending on display type and processing mode.
For competitive gaming, the total pipeline should be under 50 ms. For top-tier esports, pros aim for under 25 ms. Anything above 80 ms feels noticeably laggy in fast-twitch games.
Typical input lag of common setups
| Setup | Typical total input lag | Notes |
|---|---|---|
| Office PC, 60 Hz monitor, office mouse | 80-150 ms | Includes 30-50 ms display lag, 8 ms mouse polling, ~30 ms render time at 60 FPS. |
| Gaming PC, 144 Hz monitor, 1000 Hz mouse | 30-50 ms | Game mode enabled, VSync off. The sweet spot for competitive play. |
| Esports PC, 240 Hz monitor, 1000 Hz mouse | 20-30 ms | Pros benefit from this. Diminishing returns above 240 Hz. |
| Esports PC, 360 Hz monitor, 8000 Hz mouse | 15-25 ms | Top-tier setups. Only worthwhile for professional players. |
| Console (PS5/Xbox Series X) on TV | 60-150 ms | TV picture processing adds 30-100 ms. Enable Game Mode to drop to 30-50 ms. |
| Cloud gaming (Stadia/GeForce Now) | 80-200 ms | Network latency dominates. Only viable for non-competitive games. |
How to reduce input lag step by step
Reducing input lag is mostly about removing delays, not adding speed. Here is the priority order:
- Enable Game Mode on your TV or monitor. This disables picture processing (motion smoothing, upscaling, colour correction) that adds 30-100 ms. The single biggest free win for most setups.
- Use the highest refresh rate your monitor supports. Each step from 60 Hz to 144 Hz saves about 5-7 ms of display latency.
- Disable VSync in-game. VSync forces the GPU to wait for the monitor, adding up to one frame of latency. Use G-Sync or FreeSync instead, or accept tearing.
- Use a wired gaming mouse at 1000 Hz. Wireless mice add 1-5 ms; 125 Hz mice add 4-8 ms.
- Lower in-game graphics settings. Faster frame times mean newer input data in each frame. Going from 60 FPS to 144 FPS saves about 5 ms of render latency.
- Use Fullscreen Exclusive mode, not borderless windowed. Windowed mode goes through the desktop compositor, which adds 1-2 frames of latency on Windows.
- Disable hardware acceleration in browsers (only for browser games). Browser compositing adds latency; native rendering is faster.
Frequently asked questions
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