Quick Answer: Input lag is the delay between an action — a click, a key press, a controller input — and the monitor actually showing it, separate from response time (how fast a pixel changes color). RTINGS’ lab testing puts the average gaming monitor at roughly 11.7ms at 60Hz and 5.5ms at 120Hz, and under 10ms is considered excellent. The single biggest free fix is switching on Game Mode (or Instant Mode/Low Latency Mode), which bypasses image processing that otherwise adds 5-15ms of delay for no visible benefit during gameplay.
Input lag gets blamed for a lot of things it isn’t, and confused with a lot of things it isn’t either — most often response time, which is a completely separate spec measuring how fast a pixel physically shifts color rather than how long the signal takes to get displayed at all. Here’s how to tell the two apart, test for input lag without a lab, and actually reduce it.
Input lag vs. response time, side by side
| Input lag | Response time (GtG) | |
|---|---|---|
| What it measures | Delay from input to on-screen change | Speed of a pixel changing color |
| Caused by | Signal processing, scaling, image enhancement features | Panel/pixel technology (OLED, fast IPS, VA) |
| Typical good number | Under ~10ms | Under ~5ms GtG |
| Fixed by | Game Mode, disabling post-processing, wired connections | Panel choice — not a settings fix |
| Feels like | A delay between action and result | Motion blur or smearing during fast movement |
How to test it without lab equipment
- Slow-motion phone camera method. Put a millisecond stopwatch app on screen (or use a second synced display), film both the stopwatch and the monitor’s reaction to an input at your phone’s highest slow-motion frame rate (120-240fps), then count the frame gap between the stopwatch’s readout at the moment of input and the on-screen change. Divide the frame count by the fps to get an approximate millisecond figure.
- Rule out Game Mode first. Before testing, confirm Game Mode/Instant Mode is on — testing with it off measures a worst-case number that doesn’t reflect how you’d actually use the display.
- Test at native resolution and refresh rate. Running a lower resolution or refresh rate than the panel’s native spec can add scaling overhead that inflates the reading.
- Compare wired vs. wireless if using a controller or mouse. Wireless input devices add their own latency on top of the display’s — isolate the monitor by testing with a wired connection first.
What actually causes input lag — and the free fixes
- Image-processing features left on. Noise reduction, dynamic contrast, motion smoothing, and sharpening filters all add processing time before the frame reaches the panel. Switching to Game Mode, Instant Mode, or Low Latency Mode (naming varies by brand) bypasses this pipeline entirely and typically claws back 5-15ms for free.
- Upscaling and interpolation. Running a non-native resolution forces the display to scale the image, which adds a processing step. This matters more on cheaper monitors with slower scalers. Native resolution avoids it entirely.
- Low refresh rate. Refresh rate sets a hard floor under total lag: a 60Hz panel refreshes every 16.67ms, a 144Hz panel every 6.94ms, and a 240Hz panel every 4.17ms, so a faster panel has less time for a frame to sit waiting to display even before any processing delay is added.
- HDR and local dimming processing on budget panels. Some lower-end monitors add measurable lag when HDR or full-array local dimming is active, because the panel has to analyze the frame for zone-brightness before displaying it. Testing with HDR toggled off isolates whether it’s the culprit.
Monitors built around minimal input lag
LG UltraGear 27GS95QE — Best for Competitive Gaming
- QD-OLED's self-emissive pixels remove the response-time side of the lag equation almost entirely, and LG's Instant Mode strips image processing down to the minimum needed to display the signal.
- 240Hz refresh keeps the frame-to-frame ceiling under 4.2ms even before Instant Mode is applied.
- The panel competitive players reach for first when input lag specifically — not just smoothness — is the deciding factor.
Outfitting more than one desk with a low-lag panel — a home office, a shared gaming setup, a small studio? A free Amazon Business account unlocks quantity discounts and tax-exempt purchasing if you’re buying more than one.
ASUS TUF Gaming VG258QM — Best Budget Low-Lag Pick
- Ships with an ELMB (Extreme Low Motion Blur) mode and a straightforward Game Mode that keeps processing overhead minimal without hunting through menus.
- 280Hz refresh gives a sub-3.6ms frame-to-frame ceiling at a fraction of the price of an OLED panel.
- The pick if low input lag matters more than color accuracy or panel type for your use case.
Input lag by the numbers
- 11.7ms. RTINGS’ database average input lag for gaming monitors tested at 60Hz across hundreds of panels under identical lab conditions using a Leo Bodnar hardware lag tester.
- 5.5ms. The same database’s average at 120Hz — roughly half the 60Hz figure, showing how much of the improvement at higher refresh rates comes from the shorter frame window alone.
- 4.17ms. The theoretical frame-to-frame ceiling at 240Hz (1000ms ÷ 240), versus 16.67ms at 60Hz — the refresh-rate floor that no amount of processing optimization can beat.
- 5-15ms. The typical delay added by image-processing features (noise reduction, dynamic contrast, motion smoothing) that Game Mode or Instant Mode bypasses, per manufacturer and independent testing documentation on the setting’s effect.
The bottom line
Input lag and response time get lumped together constantly, but they’re separate problems with separate fixes — response time is a panel-technology choice made at purchase, while input lag is mostly a settings fix you can make in two minutes by switching on Game Mode. If you’ve already done that and still feel a delay, the panel’s native refresh rate is the next lever: a 240Hz monitor or faster gives less room for lag to hide even before any processing is involved. Confusing input lag with how fast a pixel itself changes color? Our monitor response time guide breaks down that separate spec. Not sure which refresh-rate tier is even worth it? Our monitor refresh rate explained guide breaks down 60Hz through 500Hz and who each tier is actually for. Still deciding on panel type entirely? Our OLED vs IPS comparison covers the response-time side of this same decision. Weighing a monitor against a big-screen TV for gaming instead? Our gaming monitor vs TV comparison breaks down exactly how much lag a TV’s Game Mode adds versus a dedicated monitor.