Monitor Input Lag Test
Use the Reaction Timer above — click when the screen turns green — to feel how responsive your display is. Run it with Game Mode on and off, or on two devices, to see how much the display contributes to the lag you feel.
New to this? Here’s the plain-English version.
What this test is
A reaction timer and moving targets that gauge how quickly your screen responds to your input — the “feel” of lag.
How it helps you
It helps you tell whether a game feels sluggish because of your display, and confirms that turning on Game Mode actually helped.
What we’re checking
Your rough total input latency, and whether Game Mode or a higher refresh rate makes the display feel snappier.
Click to start, wait for the screen to turn green, then click as fast as you can. Your time bundles your own reaction with system and display latency — run it on two devices to feel the difference a snappier display makes. Under ~250ms is quick.
Press F11 or Full Screen · ← → patterns · Esc to exit
How to Use the Test
This is a relative indicator, not a lab instrument — your reaction time includes you, your GPU, and the display. Its power is in comparison: change one thing (Game Mode, refresh rate, or the whole device) and see how the number and the feel shift.
- 1Run the reaction timer. On the Reaction Timer pattern, click to start, wait for green, then click as fast as you can. Note your best time.
- 2Compare devices or settings. Run it again after enabling Game Mode, or on another display, under the same conditions. The change reflects display responsiveness.
- 3Feel the click response. On the Click Response pattern, click and watch how instantly the panel flashes — perceptible delay is input lag.
- 4Close background load. GPU and CPU load affect the result as much as the display, so close other apps for the cleanest read.
Input Lag vs Response Time
Reviews confuse these constantly. They are independent specs measured in different ways — a monitor can be great at one and poor at the other.
Input lag
Delay from your action to the visual result. Determines how responsive the display feels. This test measures its practical effect.
Response time (GtG)
How fast a pixel switches colour. Determines ghosting, not responsiveness. Measured by the response time test.
What Input Lag Numbers Mean for Gaming
| Input lag | Gaming suitability |
|---|---|
| Under 3ms | Imperceptible; excellent for competitive play |
| 3–5ms | Excellent; recommended for competitive gaming |
| 5–10ms | Good; fine for most gaming including competitive |
| 10–20ms | Perceptible in fast games; OK for casual |
| Over 20ms | Noticeable delay; avoid for competitive/action |
Most modern gaming monitors with Game Mode on measure 3–10ms. TVs used as monitors often sit at 15–40ms without Game Mode — which is exactly why the setting exists.
What Affects Input Lag
Game Mode / Low Latency
The most impactful setting. Disabling post-processing removes 5–20ms. Always enable it for gaming.
Refresh rate
Higher Hz lowers the maximum frame latency — up to 16.7ms at 60Hz drops to 6.9ms at 144Hz.
Variable refresh (G-Sync/FreeSync)
Adds roughly 1–2ms on average in exchange for eliminating tearing — a trade-off most consider worthwhile.
Image processing
Motion smoothing, edge enhancement, and noise reduction each add delay. Turn them off for responsiveness.
Confirm your monitor is actually running at its rated speed with the refresh rate test — a panel stuck at 60Hz caps how responsive it can ever feel.
Input Lag FAQ
What is monitor input lag?+
What is the difference between input lag and response time?+
How do I reduce input lag on my monitor?+
Does Game Mode really reduce input lag?+
Is this reaction test measuring my monitor or me?+
What is a good input lag for gaming?+
Does refresh rate affect input lag?+
Related Monitor Tests
Checking a whole new panel?
Run the dead pixel test and browse the full monitor test suite.