Motion Blur / UFO Test

How to use the motion test

A white square with a dark center crosses a plain gray field from left to right, again and again, at the speed you choose. Watch its edges as it moves. On a display with fast, clean motion the edges stay fairly sharp; slower pixels and longer frame times smear them into trails.

1. 1

   Pick a speed and press Start. 960 pixels per second is a good first choice.

2. 2

   Follow the square with your eyes. Tracking it, as you would a moving object in a game or video, shows blur the way you normally see it.

3. 3

   Compare speeds and settings. Try the display's refresh rate and overdrive or response-time settings, then look again.

What you might see

Blur: soft, stretched edges. Much of it comes from the way displays hold each frame until the next one, so a higher refresh rate usually looks sharper. Ghosting: a faint trailing copy behind the square, caused by pixels that change slowly. Bright or dark halos along the edges can come from overdrive set too high, which pushes pixels past their target.

Motion also depends on the frame rate the browser actually achieves. Check it with the Refresh Rate Test, and look for torn frames with the Screen Tearing Test. Refresh Rate Explained explains where blur comes from.

Settings that change motion

Refresh rate: set the highest rate your display supports in the operating system's display settings. Overdrive or response time: the middle setting is often the best balance between trails and halos. Blur reduction: some displays offer a mode that pulses the backlight to sharpen motion. It visibly flickers for some people, so leave it off if flicker bothers you. After each change, run the test again at the same speed.