A moving object, an adjustable speed, and three backgrounds — watch for a trail behind it to check your monitor's motion clarity and tune its overdrive setting.
RUNS ENTIRELY IN YOUR BROWSER · NOTHING IS RECORDED OR UPLOADED
Last updated: · Reviewed for accuracy against current browser APIs
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Watch the object below. Look for any trail, smear, or halo following it.
Start with black — dark scenes reveal the most ghosting, especially on VA panels.
Set a realistic speed.
Match the speed to what you actually do: slower for office work and reading, faster for gaming and fast video.
Watch the trail, not the object.
Follow the moving block with your eyes and pay attention to what's happening just behind it.
Try fullscreen.
Browser chrome and other page content can distract from a clean read — fullscreen removes that.
Repeat at each overdrive setting.
If you can adjust Response Time or Overdrive in your monitor's menu, re-run the test at each level to find the cleanest one.
How this test actually works
The moving block is drawn on an HTML canvas element and repositioned every frame using requestAnimationFrame, the same browser API that drives smooth web animations and games — its position is calculated from real elapsed time rather than a fixed step, so the speed you set in pixels per second stays accurate regardless of your monitor's own refresh rate. What you actually see beyond that point is entirely down to your display's hardware: how quickly its pixels can physically change color from one frame to the next.
That's worth being upfront about, because it's the honest limit of any browser-based test like this one. A lab-grade response time measurement needs a high-speed camera capturing hundreds or thousands of frames per second — nothing running in a browser tab can measure gray-to-gray transition time in actual milliseconds. What this tool is genuinely good for is comparison: the same moving pattern, at the same speed, let's you judge one overdrive setting against another, or one monitor against another, by eye.
Understanding what you see
A soft trail or smear behind the object
This is classic ghosting — the pixels are still finishing their color transition after the object has already moved on. A longer, more visible trail means slower pixel response. This is the pattern to watch for most closely on a black background, since dark-tone transitions are usually the slowest on any given panel.
A bright or dark halo just ahead of the object
This is inverse ghosting, also called overshoot or corona — the opposite problem. The panel's overdrive circuitry is pushing pixels too aggressively, overshooting the target color before settling. It's just as much a motion-clarity issue as ordinary ghosting, and it means your current overdrive setting is a step too high.
A sharp edge with no visible trail
This is what a genuinely fast panel looks like at this speed. OLED displays typically show this at almost any speed; a well-tuned IPS or TN panel should get close to it too.
A stepped or strobing trail, rather than a smooth smear
This points toward the refresh rate itself rather than pixel response — the object is visibly "jumping" between positions instead of gliding. Compare against our Refresh Rate Test to check what your display is actually outputting.
Tuning your overdrive setting
Most gaming monitors expose this setting in their on-screen menu under a name like Response Time, Overdrive, or OD, usually with levels such as Off, Normal, Fast, and Extreme. There's no universally correct level — it depends on your specific panel — so the only reliable approach is testing each one directly.
Start from Off or the lowest level.
Run this test at your usual speed and note how visible the trailing is.
Move up one level at a time.
Re-run the test after each change rather than jumping straight to the highest setting.
Watch for the switch from trailing to haloing.
The moment you start seeing a bright edge ahead of the object instead of a smear behind it, you've gone one level too far.
Settle on the level just before that point.
That's typically the cleanest motion your panel can produce — minimal trail, no overshoot.
Turn off VRR (FreeSync or G-Sync) while doing this specifically, since some monitors quietly change their overdrive behavior when VRR is active, which can make the comparison inconsistent between settings.
Panel types and ghosting
Panel type
Typical ghosting behavior
VA
Best contrast and black levels, but the slowest dark-tone transitions of any common panel type — this is where VA smearing shows up most
IPS
Generally light, consistent ghosting across most color transitions; a common choice for a balance of color accuracy and motion clarity
TN
Historically the fastest LCD type with the least ghosting, though largely replaced by fast IPS panels in newer monitors
OLED
Near-instant pixel response with essentially no traditional ghosting — remaining motion blur comes from sample-and-hold, not pixel speed
Ghosting vs. input lag vs. screen tearing
These three get confused constantly, but they're genuinely different problems. Ghosting is a visual trailing effect caused by slow pixel response — it's about what the panel looks like, and this test targets exactly that. Input lag is a timing delay between an action (a mouse click, a controller input) and when its result appears on screen — it's invisible to the eye and needs a different kind of test entirely. Screen tearing looks like a horizontal split across the image, caused by the display and graphics card falling out of sync, fixed by enabling VSync or a variable refresh rate technology rather than anything to do with pixel response.
Frequently asked questions
What does ghosting actually look like?
A faint, semi-transparent copy of the moving object trailing behind it, like a smear or shadow. On a clean, fast panel the object should look sharp with little to no visible trail behind it.
Is ghosting the same as screen tearing?
No. Ghosting is a trailing smear caused by slow pixel response. Screen tearing looks like a horizontal split in the image, caused by the display and the graphics card being out of sync — a completely different problem with a different fix.
Why does my monitor ghost more on a black background?
VA-panel liquid crystals are naturally slower transitioning into and out of black than most other color transitions, so dark-scene ghosting is a known, common weak point for that panel type — it doesn't necessarily mean the monitor is defective.
Can browser-based testing give me an exact response time in milliseconds?
No. An accurate gray-to-gray or MPRT measurement needs a high-speed camera or dedicated hardware. This test is a genuinely useful visual comparison tool, not a lab-grade measurement.
I see a bright halo in front of the object instead of a trail behind it — what's that?
That's inverse ghosting, also called overshoot or corona, caused by an overdrive setting that's too aggressive. Lower the Response Time or Overdrive level in your monitor's on-screen menu by one step and test again.
Does a higher refresh rate fix ghosting?
Not by itself. A higher refresh rate demands faster pixel transitions to keep up, so a panel with genuinely slow response can actually show more ghosting at 144Hz than it did at 60Hz.
Does this test record or upload anything?
No. Everything runs locally on a canvas element in your browser — nothing is recorded, saved, or sent anywhere.
More tools on ProDeviceTest
Motion clarity is just one piece of overall display quality. These cover the rest.
Refresh Rate Test — measure what your display is actually outputting right now
Dead Pixel Test — cycle through solid colors to spot dead or stuck pixels
ProDeviceTest