Monitor Response Time Test

Monitor response time is the time it takes for a pixel to change from one color to another, measured in milliseconds (ms). A slower response time causes pixels to lag behind the moving image, producing visible "ghosting" or smearing behind fast-moving objects. For gaming, a fast response time (1-4ms GTG) minimizes motion blur and ghosting, giving you a sharper image during fast action. For productivity and video work, response time matters less. The most common specification is GTG (gray-to-gray), which measures transitions between gray levels.

Ghosting is a visual artifact where a faint "echo" or trail appears behind a moving object on screen. It is caused by pixels not completing their transition before the next frame is displayed. This test uses a white circle moving across a dark background — if you see a faint trail or shadow behind the circle, your monitor is ghosting. The severity of ghosting depends on your monitor's response time setting and the specific pixel transition being tested. Dark-to-light and light-to-dark transitions often have different response times.

Inverse ghosting (also called coronas or overshoot) appears as a bright or differently-colored halo in front of a moving object rather than behind it. It is caused by overdrive being set too aggressively — the monitor overcompensates for slow pixel transitions by pushing the pixel voltage higher than needed, causing it to overshoot its target color. If you see a bright leading edge ahead of the moving circle in the UFO test, your monitor's overdrive is too high. Check your monitor's OSD settings for an "Overdrive," "Response Time," or "AMA" setting and reduce it.

GTG (gray-to-gray) measures how long a single pixel takes to transition between two gray levels. MPRT (moving picture response time) measures the total perceived blur including both pixel response time and the effect of sample-and-hold displays — it is a closer measure of actual visual performance. Input lag is the delay between your input (mouse click, controller button) and the display showing the result — it includes both monitor processing delay and pixel response time. This test specifically evaluates pixel-level ghosting artifacts, which are related to GTG response time and overdrive settings.

OLED panels are the fastest, with pixel response times under 0.1ms — effectively instantaneous. Among LCD technologies, TN panels are traditionally the fastest (1ms GTG) but have poor color and viewing angles. Fast IPS and Nano IPS panels now achieve 1-4ms GTG with much better color and viewing angles, making them the most popular for gaming. VA panels have historically been the slowest, with aggressive overdrive needed to reach competitive response times — this often causes inverse ghosting on VA panels. Modern premium VA panels have improved but still typically lag behind IPS.

No. Maximum overdrive reduces ghosting but typically introduces inverse ghosting (coronas) that is often more visually distracting than mild ghosting. The optimal setting depends on your monitor and refresh rate — higher refresh rates generally allow more aggressive overdrive settings without visible coronas. Use this test to find the best overdrive setting: enable Medium or Fast overdrive, run the UFO test at your gaming speed, and look for the balance between minimal ghosting behind the object and no visible bright halo in front of it.

Even monitors with 1ms GTG response times exhibit motion blur during fast motion. This is because most monitors are sample-and-hold displays — they hold each frame static until the next frame arrives. Your eyes naturally track moving objects, causing them to integrate the held image over the entire frame period, which appears as blur. This is different from ghosting artifacts. ULMB (Ultra Low Motion Blur), ELMB, and similar backlight strobing technologies address this by flashing the backlight only during the refresh, reducing perceived motion blur even further.

Match the test speed to your typical gaming scenario. For competitive FPS at 240Hz, set it to 240. For 144Hz gaming, use 144. For casual gaming at 60Hz, use 60. The faster the speed, the more ghosting artifacts become visible. Start at your monitor's refresh rate — if you see no ghosting there, try a higher speed to stress-test the panel. Slower speeds are useful for checking overdrive coronas, which appear more prominently at lower speeds.

No — this is a visual test for qualitative ghosting assessment, not a quantitative measurement tool. Measuring response time in milliseconds requires specialized hardware (like a Blur Busters or Leo Bodnar controller) that can strobe a backlight and capture pixel transitions with a photodiode. This test tells you whether ghosting is visually perceptible at your settings, which is more practically useful for gaming. For quantitative numbers, refer to professional monitor reviews from sites like rtings.com or blurbusters.com.