Reaction Time, Motion Blur, Ghosting & UFO Test — Screen Response Checker
Three display tools on one page, no tabs to dig through. Test your reaction and screen response time, watch a live motion blur / ghosting demo, and run the classic UFO test to inspect pixel response — scroll down or jump straight to any tool below.
1Display and Screen Reaction Time and Response Time
Wait for the red screen to turn green, then click or tap as fast as you can. This measures your full stimulus-to-click chain — your reflexes plus your monitor's own input and pixel-response lag — across several rounds.
📊 Reaction Tiers
Example data — run the test to see your results
🕐 Recent Results
No tests completed yet.
2Motion Blur Test and Ghosting Test
An object sweeps across the stage on a loop. Watch its edges as it moves — a fast, clean panel keeps the edges sharp, while a slower panel shows a smeared trail (motion blur) or a faint duplicate image following behind (ghosting). This is a visual test: look at your own screen, not a number.
3UFO Test and Pixel Response
The classic multi-row UFO motion test — several UFOs cross the stage at different relative speeds so you can compare trailing side by side. Switch to Flash Mode to alternate the whole screen between black and white, which is the simplest way to eyeball how fast your panel's pixels actually rise and fall.
Reaction Time vs. Screen Response Time
Your reaction time is how long your brain and hand take to respond once you see a change — average adult reaction to a visual cue is roughly 200–250ms. Screen response time is separate: it's how fast your monitor's pixels physically change color, usually just a few milliseconds. This test measures the combined total, so a slower monitor will nudge every result up slightly. Pair this with our refresh rate or hz test to see the other half of display responsiveness.
What Causes Motion Blur and Ghosting
Motion blur on an LCD or OLED panel happens because each pixel takes a small but nonzero amount of time to switch from one color to the next — while it's mid-transition, moving content looks smeared. Ghosting is a more extreme version where a faint duplicate of the object trails behind, usually caused by a slow pixel response combined with overdrive settings that overshoot or undershoot the target color. A dropped or unstable frame rate makes blur more noticeable too, so it's worth checking with our frame rate or fps test if trails seem worse than expected.
Why the UFO Test Uses Multiple Speeds
Showing several rows at different relative speeds lets you compare trailing side by side rather than guessing from a single moving object. A crisp, well-controlled panel keeps a tight, defined UFO shape even in the fastest row, while a slower or poorly-tuned panel shows an increasingly long trail as the row speed goes up. Since trailing length also depends on your monitor's refresh rate, it helps to confirm it with our hz test.
Reading the Pixel-Response Flash Test
Flash Mode swaps the whole screen between black and white on a timer, which is one of the simplest ways to see rise and fall response with your own eyes. If you notice a lingering gray "afterimage" of the previous frame right after the switch, that's your panel's pixels still catching up — a classic sign of slower gray-to-gray response time. It's worth confirming your actual frame rate first with our fps test, since a low or unstable rate can make response issues harder to judge.