Two specs, two different things
GtG and MPRT both appear on monitor spec sheets as "response time," but they measure completely different things. Mixing them up is one of the most common mistakes when shopping for a fast gaming monitor.
GtG (Gray-to-Gray) measures how long a single pixel takes to change from one gray shade to another. It is a hardware property of the LCD panel itself.
MPRT (Moving Picture Response Time) measures how long a pixel appears to be visible to the human eye during motion. It is largely a backlight strobe metric, not a panel metric.
A monitor can have a 1ms MPRT rating while still having a 4ms GtG panel. These are not competing claims.
What GtG actually measures
GtG is tested by sending a pixel from one gray value to another (for example 10% gray to 90% gray) and recording the milliseconds it takes to complete the transition. A lower number means pixels change faster, which reduces the smearing trail you see behind moving objects.
Typical GtG ratings by panel type:
The GtG number brands advertise is almost always the best-case overdrive measurement, not the typical number across all gray transitions. A "1ms GtG" IPS monitor often has 4-6ms on darker transitions where overdrive is less aggressive.
What MPRT actually measures
MPRT is dominated by how long the backlight is on per frame, not how fast the panel is. When a monitor uses backlight strobing (also called blur reduction, 1ms MPRT, or ULMB), the backlight flashes once per frame instead of staying on continuously.
The human eye perceives motion blur partly because a pixel stays visible for the entire frame duration. At 60Hz, each frame lasts 16.7ms even if the pixel changed in 4ms. The pixel is visible for 16.7ms of your eye movement. Strobing reduces that perceived blur by only showing the image for a short flash.
MPRT numbers in the range of 0.5-1ms are achieved by extremely short strobe pulses. This has nothing to do with how fast the LCD panel switches.
Which one affects ghosting?
Ghosting is caused by slow GtG transitions. When a pixel cannot switch fast enough, it leaves a visible trail behind moving objects. This is a panel speed issue and is only improved by faster panels or overdrive.
MPRT does not fix ghosting. A pixel that takes 10ms to switch will still ghost even with strobing enabled, because the strobe only controls when the backlight fires, not when the pixel finishes transitioning.
If you see a trail following fast-moving objects on a dark background, that is ghosting from slow GtG. Use our Ghosting Test tool to check your monitor.
Which one affects motion clarity?
Motion clarity (how sharp objects look while moving) is affected by both, but differently.
Sample and hold blur comes from continuous backlight. Even a 1ms GtG panel will show motion blur on a continuous backlight display because the eye tracks the motion across the full frame duration. This is reduced by high refresh rate or backlight strobing.
Pixel transition blur comes from slow GtG. This compounds sample-and-hold blur and makes fast motion look smeared in two ways at once.
The best motion clarity comes from OLED with a fast refresh rate. OLED has near-instant GtG and can strobe effectively.
How monitor brands inflate these numbers
Several practices are common in spec sheet marketing:
Cherry-picked GtG: Testing only the fastest overdrive setting, which often introduces inverse ghosting (white halos), and reporting that number.
MPRT presented as GtG: Listing "1ms response time" without specifying it is MPRT. The actual GtG on that IPS panel might be 4ms.
Overdrive at any cost: Setting overdrive so aggressively that overshoot artifacts become visible at normal use. The 1ms number is real, but the image quality is worse.
Slow dark transitions hidden: VA panels in particular can have fast typical transitions but very slow dark-to-dark transitions that are not represented in the advertised number.
What to look for when buying
For competitive gaming (CS2, Valorant, Apex): prioritize actual GtG at the overdrive setting you will use. Read professional reviews like RTINGS that measure real GtG curves, not spec sheet numbers.
For cinematic gaming and general use: motion clarity at your chosen refresh rate matters more than absolute GtG. A 165Hz IPS with 4ms GtG will look sharper than a 60Hz panel with 1ms GtG.
For the absolute best motion: OLED panels have pixel response times under 0.1ms GtG, eliminating both pixel transition blur and sample-and-hold issues at high refresh rates.
Testing on your own monitor
Our Response Time Test tool shows horizontal bars moving across your screen. At default (no overdrive) you should see some trailing. Enable your monitor overdrive setting and refresh the test. The trailing should reduce. If you see a bright halo or white outline behind moving objects, overdrive is set too high.
At the same time, check our Ghosting Test tool which uses the UFO motion test pattern. This gives a visual benchmark for motion clarity at your current refresh rate and settings.