DeviTestMonitor ghosting test
Objects move across the screen at different speeds. Watch their edges to see how clean the motion is.
Runs right here in full screen — nothing is uploaded. Press Esc or ✕ to exit.
What to look for
- Ghosting: a faint copy or smear trailing behind the moving object. It means pixels change color slowly.
- Overshoot (inverse ghosting): a bright or colored halo behind the object. It usually comes from an overdrive setting that's too strong.
- General blur: the whole object looks soft while it moves. Some blur is normal on any screen that holds each frame until the next one.
How to run the test
- Start the test and follow one moving object with your eyes, not a fixed spot.
- Compare the slow, medium and fast lanes.
- Try the BFI option (black frame insertion), which flashes black between frames to reduce blur. It may flicker on 60Hz screens.
How to reduce ghosting
On a monitor, look for a setting called Overdrive, Response Time or Trace Free and try the middle level, which often gives the best balance. Running the screen at its highest refresh rate also helps. On phones, ghosting is common on older OLED panels in dark scenes and usually can't be changed.
This test lets you see motion quality, but no browser can measure response time in milliseconds. Read response time and ghosting explained to learn what GtG and MPRT mean.
Frequently asked questions
Can this test measure response time in milliseconds?
No. A browser can't measure how fast pixels change; that needs a camera or a light sensor. The test shows the trails so you can compare settings or screens with your own eyes.
What is overshoot?
When a monitor's overdrive is set too high, pixels change past their target color, leaving a bright or dark halo behind moving objects. If you see an inverted-color trail, lower the overdrive setting.
Why is BFI only available on fast screens?
Black frame insertion shows a black frame between images. On a 60 Hz screen that would be 30 flashes per second, which is uncomfortable and unsafe for some people, so it's only enabled at 100 Hz or more.