Monitor Ghosting Test: Check Overdrive and Motion Blur
Monitor Ghosting Test. Pick a Test preset and Speed in this monitor ghosting test to see trails and overshoot behind a moving block. Use the screen uniformity test to confirm whether your monitor shows this issue before you adjust settings or return it.
Interactive Tool
Ghosting Test
Watch the moving block glide across each lane. A clean, sharp edge with no trailing smear means good motion handling; a faint duplicate trailing behind it (or a bright overshoot in front) points to ghosting or overdrive set too high.
Raise the text speed until the moving text is no longer cleanly readable; that is your motion readability threshold.
The Monitor Ghosting Test slides a block across light and dark lanes at a speed you set, so you can watch for a trailing smear or a bright overshoot behind the moving edge — the visual signature of ghosting or overdrive pushed too far. Drag the Speed slider to match your typical content, then look at both lanes: a clean edge with no shadow means your overdrive setting is dialed in, while a duplicate ghost trailing or leading the block means it's worth backing your monitor's overdrive down a notch.
Moving patterns on a monitor ghosting test reveal what a spec sheet hides: whether your pixels keep up with a moving object or leave a faint trailing smudge behind it. In two minutes you get a clear read on your display's motion smoothness, overdrive behaviour and real-world response.
How the Monitor Ghosting Test Tool Works
High-contrast moving targets slide across a plain field, timed by your browser's requestAnimationFrame so each frame lands on a refresh. GPU drivers and system load can shift results, so run it in fullscreen.
Speed, Crosshair and Background Controls
Three controls shape each run. Speed sets travel per second in px/s: slow mimics office scrolling, middle video playback, fast a gaming flick. The crosshair gives you a sharp edge, and the background switch changes what it moves over. Follow it with your eyes rather than a fixed spot; this pursuit is how you view motion in a game.
Moving Text and Readability Checks
A scrolling line of moving text makes the result practical: raise the speed until the words stop reading cleanly. That point is your readability limit, and comparing it across settings is a quick monitor test of whether one mode adds visible stepping or smudging.
What Ghosting Looks Like in a Monitor Test
Ghosting is a faint copy of the previous frame following anything in motion, a shadow or afterimage left because the pixels have not finished changing colour. It takes three forms.
Trails Behind Moving Blocks
A soft, semi-transparent trail behind moving blocks means slow color transitions. Watch the trailing edges: a longer tail means a slower change, and it usually grows as you raise the speed.
Inverse Ghosting and Overshoot Halos
Inverse ghosting is the opposite fault. When the monitor applies extra voltage to push each pixel cell faster (overdrive), the cells overshoot the target colour and paint a bright halo, sometimes called corona, ahead of or around the edge. Bright or dark halos mean the overdrive is too aggressive, not too weak.
Ghosting vs Motion Blur
Not every smudge is ghosting. Motion blur also comes from eye tracking on a sample-and-hold display: each frame is held still while your eyes keep moving, so the image spreads across your retina even when pixel transitions are instant. Ghosting is fixed by faster panels or overdrive; hold-type blur is fixed by shorter frames or strobing.
Pixel Response Test Numbers: GtG and MPRT
A browser can't measure these precisely (that needs high-speed capture hardware), but they explain what you see.
Pixel Response Time and the 1ms Claim
Pixel response time is usually quoted as GtG, or gray-to-gray: how long a pixel takes to move between two grey levels. The "1ms" on the box is normally the single fastest grey to grey change, not the average. Dark-to-bright changes are often several times slower, which is why a 1ms panel can still leave a visible trail.
MPRT, Persistence and Blur Width
MPRT (moving picture response time) adds the hold effect on top of GtG. On a hold-type panel each frame stays lit for one full refresh, the frame hold time, so the persistence floor at 60Hz is 16.67ms. You can turn that into a blur width:
$$B = \frac{v}{f}$$
where \(B\) is the smear width in px, \(v\) the target speed and \(f\) the refresh frequency in Hz. Take a target at 1,120 px/s on a 165Hz panel: each frame lasts 6.06 ms, so \(B = 1120 \div 165 \approx 6.8\) px. At 60 Hz it spreads about 18.7 px. A slow 18 ms dark change adds roughly 20.2 px of trail on top, so the pattern can look worse than the formula predicts.
How to Test for Ghosting and Set Overdrive
Overdrive briefly drives the liquid crystal with a stronger signal so it rotates faster. Every overdrive mode trades leftover trail against overshoot, so the job is finding your balance point.
Overdrive Settings in the OSD Menu
- Open the OSD menu and find Overdrive, OD or Response Time.
- Start at Off and step up one level at a time at the same speed.
- At each level, note the trail length and whether a bright overshoot halo appears.
- Keep the highest of the overdrive settings that shortens the trailing without adding halos.
Native Refresh Rate and Background Checks
Confirm your operating system and the monitor both report the native refresh rate first; anything quietly running at 60 Hz misleads every reading. Then repeat each setting on a black background and a white background, since dark transitions are often much slower than bright ones.
Tuning a 170Hz VA Panel with the Motion Clarity Test
A friend's new 27-inch VA screen runs at 170Hz, and in a dark extraction shooter every enemy in a doorway drags a brown streak. The decision is simple: which OD level to keep, and whether the refresh needs to change too. The short answer turns out to be Fast, with dark games capped at 120Hz.
I set the moving pattern to 1,380 px a second on the black field, because that matches a quick mouse swipe at his sensitivity, and use the 24 px crosshair arm as a ruler. At 170Hz one refresh lasts 5.88 ms, so even a perfect panel shows about 8.1 px of hold blur (1,380 ÷ 170). Anything longer is the liquid crystals lagging.
Stepping through each OD level, I read the streak length and convert it to time by dividing by the speed:
| OD level | Streak (px) | Implied transition (ms) | Refresh windows at 170Hz |
|---|---|---|---|
| Off | 31 | 22.5 | 3.8 |
| Normal | 19 | 13.8 | 2.3 |
| Fast | 12 | 8.7 | 1.5 |
| Faster | 8 | 5.8 | 1.0 |
The reference I judge against is the one reviewers call refresh rate compliance: a transition should finish inside one refresh window. Faster looks like it passes at 1.0, but switching to the gray field shows why I don't trust that row. A pale fringe now runs ahead of the block, and on the dark field that fringe hides part of the streak, so the shorter reading is partly an illusion.
So Fast it is. The sensitivity rerun is the useful bit: drop the cap to 120Hz and the window grows to 8.33 ms, which puts Fast's 8.7 ms at 1.04 windows, close to compliant. For his dark shooter he caps the game at 120; for brighter games he keeps 170, where the streak is barely visible anyway.
One caveat: reading a streak by eye against a 24 px ruler carries roughly ±3 px of error, which is ±2.2 ms at this speed. That is enough to blur the line between Fast and Faster, so the halo check, not the number, is what settles it. I'd also turn off FreeSync for the reading, since this ghosting estimate changes when frame rates dip and the OD tuning shifts with them.
Screen Test Results by Panel Type
The same pattern looks very different on each type of LCD and on OLED, because panel chemistry sets how fast colours can change.
TN and IPS Panels
TN, the fastest liquid-crystal design and long the esports default, shows light trails that overdrive cleans up easily. Fast IPS comes close, with slightly slower dark transitions; a middle overdrive level suits it.
Dark-Level Smearing on VA Panels
VA panels give deep blacks but slow near-black changes, so dark-level smearing, or VA smear, lingers behind bright objects in dark scenes. Overdrive barely touches it, and pushing higher only adds bright edges.
OLED Speed and Its Limits
OLED switches in well under a millisecond, so classic ghosting all but disappears and there is no overdrive menu at all. It is still a hold-type display, though, so its motion blur depends on frame length rather than pixel speed.
Refresh Rate, VRR and BFI Fixes for Ghosting
Once overdrive is set, motion clarity improves mainly through shorter frames. Variable refresh rate (FreeSync or G-Sync) fixes screen tearing, not blur, and some models show worse overdrive artifacts when VRR drops to low frame rates, so switch it off while testing.
60Hz vs 144Hz vs 240Hz in Competitive FPS
Each step up shortens every frame: 16.67 ms at 60 Hz, 6.94 ms at 144 Hz, 4.17 ms at 240 Hz and 2.78 ms at 360Hz. In competitive FPS games that means cleaner camera pans and faster target acquisition for gaming, provided transitions finish inside each frame; otherwise a higher refresh exposes more ghosting.
Black Frame Insertion Trade-Offs
Black frame insertion (BFI), sold as ELMB or DyAc, and other strobed backlighting modes flash each frame briefly instead of holding it, cutting hold blur sharply at the cost of brightness and, at low strobe rates, flicker. Rerun the ghosting pattern with it on: the target edge should sharpen, and a faint double image means strobe crosstalk, worth it mainly at 240Hz and above.
Frequently Asked Questions
- Why does my 1ms monitor still show ghosting?
- The 1ms figure is usually the single fastest gray-to-gray transition measured under ideal conditions. Other color changes, especially dark-to-bright ones, can take several times longer, so a visible trail on the ghosting test is common even on 1ms panels.
- What does a bright edge around the moving target mean?
- A bright or dark halo ahead of or around the target is inverse ghosting, caused by overdrive pushing pixels past their target color. Lower the overdrive setting one level and run the test again at the same speed.
- Should I set overdrive to the maximum?
- Usually not. The highest overdrive level almost always adds overshoot halos. Step up one level at a time from Off and keep the highest setting that shortens the trail without a bright edge; for many monitors that is the middle option.
- Does a higher refresh rate reduce ghosting?
- A higher refresh rate shortens how long each frame is held, which cuts motion blur. It does not speed up the pixels themselves, so if transitions cannot finish inside each shorter frame, ghosting can become more visible rather than less.
- Can VA panel dark smearing be fixed?
- Only partly. VA panels change slowly near black, and overdrive helps bright transitions far more than dark ones. Testing on a gray background or raising in-game brightness reduces how often you see it.
- Does OLED have zero ghosting?
- OLED pixels switch in well under a millisecond, so classic ghosting is essentially absent. OLED is still a sample-and-hold display, though, so motion blur depends on refresh rate unless you use black frame insertion.
- Can a browser test measure true response time?
- No. A browser ghosting test lets you compare settings by eye, but exact GtG and MPRT figures need high-speed camera capture or dedicated measurement hardware. Browser timing and system load can also affect the animation.