Monitor ghosting test

How to run the test

1. Press Full screen and check that Frames per second matches your refresh rate. If it does not, fix that first with the monitor refresh rate test; low or uneven frame rates make motion look worse than the panel is.
2. Pick a Background: grey is the usual reference, black shows dark smearing on VA panels, white and cyan show other transitions.
3. Follow one object with your eyes for a few passes. Start with 240 px/s, then try the faster lanes.
4. Change the overdrive (response time) setting in your monitor's menu, one step at a time, and compare.

Reading what you see

• Even blur on the whole object that grows with speed: normal motion blur of a screen that holds each frame until the next one. Higher refresh rates and backlight strobing modes reduce it.
• A dark or grey trail behind the object: ghosting or smearing — the pixels are too slow to change. A higher overdrive setting may shorten it.
• A bright or coloured halo, lighter than the background, behind or around the edges: overshoot or inverse ghosting — overdrive is pushing too hard. A lower overdrive setting usually helps.
• Trails mainly on the black background: dark transitions are slow, which is typical of many VA panels.

Choose the overdrive setting with the shortest trail and no noticeable halo, at the refresh rate you actually use; the best setting can change with refresh rate.

Limits

• This is a visual comparison. A browser animation cannot measure response time in milliseconds; that needs a light sensor or a pursuit camera setup.
• Speeds are in CSS pixels per second, so the physical speed on screen depends on your display scaling and screen size.
• Photos taken by hand do not track the motion and show blur that your eyes do not; judge by eye.
• Animation pauses if your system asks to reduce motion; press Resume to start it.

To check whether frames are being skipped at a high or overclocked refresh rate, use the frame skipping test.