Monitor Motion Blur Test: Ghosting Test & MPRT Check
Monitor Motion Blur Test. Set the Speed in this monitor motion blur test and watch the moving square for blur and trailing. Use the screen uniformity test to confirm whether your monitor shows this issue before you adjust settings or return it.
Interactive Tool
Motion Blur Test
Track the moving square with your eyes and compare it against the stationary reference square beside the lane — perceived blur while tracking a fast-moving object comes from sample-and-hold behavior and refresh rate as much as pixel response, so a panel with a fast response time can still look blurry in motion.
Motion Blur Estimate
This monitor motion blur test sends a labelled square sliding past a stationary reference square at a speed you set with the Speed slider or the preset buttons, so you can track it with your eyes and see how much the moving square smears compared to the still one. What you're seeing is mostly sample-and-hold blur tied to your refresh rate, not just pixel response time — which is why even a monitor with a genuinely fast panel can still look blurry when you follow something moving quickly across it.
Fast pans that turn crisp text into a smudge are exactly what a monitor motion blur test is built to catch. This pursuit test slides a moving object across your screen at a set speed, so you can judge motion persistence, pixel response time and the shape of the trailing edges with your own eyes. You come away with a clear read on smoothness and readability, whether your LCD runs at 60Hz or a high 360Hz.
How the Monitor Motion Blur Test Measures Blur
The motion blur you see on a modern display is mostly display persistence, not a slow panel. Your eyes follow the image smoothly while each frame sits still, so the picture smears across your retina. That eye-tracking blur has a simple size, measured in pixels rather than milliseconds: The monitor viewing angle test works on any screen — laptop, external monitor, or TV — with nothing to install.
$$\text{Blur width (px)} = \text{speed (px/s)} \times \text{hold time (s)}$$
Run the test at 1,320 px/s on a 165Hz monitor and each frame holds for 6.06 ms, so every edge spreads across about 8 px. Drop the same monitor to 60Hz and the smear widens to 22 px.
Sample-and-Hold Persistence and MPRT
LCD screens and most modern displays are sample-and-hold: they show a frame and keep it lit until the next refresh. MPRT (moving picture response time) expresses that frame hold as a time, roughly \(1000 \div \text{Hz}\) ms when nothing strobes, which gives about 6 ms at 165Hz. A CRT instead flashed each image as a brief impulse, so it looked sharp. Persistence blur therefore shrinks only when each image is shown for a shorter time, and eye tracking does the rest.
Pixel Response Time and GtG Transitions
Response time is the second source. GtG (gray-to-gray) measures how long a liquid crystal takes to finish one transition, usually quoted in milliseconds. Slow pixel transitions leave a smeared copy behind the image. Marketing specs such as 1ms are measured on the friendliest color transitions, so real hardware often trails longer. A browser can time frames but cannot read liquid crystals; that needs a photodiode.
Running the Pursuit Test Step by Step
Open the motion test in fullscreen, away from web browser chrome. The browser paces the animation with requestAnimationFrame and V-Sync, so it moves once per refresh. Most tools also offer a crosshair for aiming, a text scroll, and a moving text test for readability at speed. The same steps apply on any monitor test page. Run the free monitor sharpness test to check your display for this issue directly in your browser — no download required.
Set the Native Refresh Rate First
Start with a refresh rate test: blur widths only hold at the monitor's rated rate. Many high refresh models arrive set to a lower one. Open your display settings (Windows: Display, then Advanced display; macOS: Displays) and pick the highest refresh rate listed. Use a DisplayPort or HDMI 2.0+ cable, update the GPU driver and keep hardware acceleration on, or a 144Hz screen can quietly fall back to 60Hz.
Choose a Test Speed and Background
Start at 960 px/s, the common reference speed, then try slower and faster speeds to see where ghosting starts. Switch the background too: dark backgrounds expose slow near-black transitions, while a mid-gray or high-contrast pattern shows overshoot. Track one target with your eyes; only moving objects you follow show the blur.
Capture the Trail with a Pursuit Camera
A photo settles arguments. Hold a smartphone camera level, pan it at the same pace as the moving image and shoot during the pan. Like real camera pans, the shot records the trail the way tracking eyes see it.
Reading Ghosting, Overshoot and Other Artifacts
Classic ghosting is a faint trail or shadow that follows the object, the sign of pixels that finish changing late. A monitor ghosting test separates it from plain blur: soft, blurry edges on both sides come from hold time, while a distinct copy behind the object points to slow response time.
Inverse Ghosting Coronas from Overshoot
Push overdrive too hard and the extra voltage drives each pixel past its goal color. The result is inverse ghosting: a bright or dark halo, sometimes several coloured coronas, leading or chasing the object. It means overdrive is one step too strong.
Dark-Level Smearing on VA Panels
Some panels with deep contrast switch slowly out of near-black, so dark objects leave a long, dirty streak known as black smearing. Compare dark and light patterns at the same speed; a streak only over dark tones is built into the design, not a setting.
Checking a New 180Hz Editing Monitor with a Ghosting Test
I have a new 27-inch 2560 × 1440 IPS monitor, sold as 180Hz and "1ms", and 11 days left in the return window. The question is simple: keep it or send it back, because scrubbing a video timeline leaves a dark tail of motion blur I did not see on my old display. The answer turned out to be keep it, after one setting change: the trail dropped from 14.3 px to 8.1 px.
First I timed my real workload. The timeline crosses the full 2,560 px width in about 2.2 seconds, so I set the custom speed to 1,164 px/s rather than a preset. The readout showed only 60 updates per second, so Windows had the panel at 60Hz. After switching it to 180Hz, the predicted pure persistence width is 1,164 ÷ 180 = 6.5 px, against 19.4 px at 60Hz.
On the gray pattern with overdrive at Normal, the pursuit photo showed a 14.3 px trail. Everything beyond 6.5 px is slow pixel switching: 7.8 px at 1,164 px/s is about 6.7 ms, longer than the 5.56 ms each refresh lasts, so transitions were spilling into the next frame. I repeated each overdrive step at the same speed:
| Overdrive | Measured trail | Excess over 6.5 px | What I saw |
|---|---|---|---|
| Normal | 14.3 px | 6.7 ms | dark tail |
| Faster | 8.1 px | 1.4 ms | clean |
| Fastest | 7.4 px | 0.8 ms | white fringe ahead |
The middle step wins: 1.4 ms of excess fits well inside one 5.56 ms refresh, and the fringe at the top step is worse for editing than the extra 0.7 px. I cross-checked the 6.5 px baseline by halving the speed to 582 px/s; the clean trail fell to 4.1 px, matching the 3.2 px of hold blur plus the same 1.4 ms (0.8 px) the formula predicts.
One trap I nearly fell into: my phone first shot at 1/1000 s, shorter than a single refresh, so the photo hid most of the trail. The shutter has to stay open for at least one refresh, so I locked it to 1/125 s. The number to watch here is the excess time, not the trail in px, because only the time stays the same when the speed changes.
Refresh Rate and Motion Clarity from 60Hz to 360Hz
Refresh rate sets how long each image stays lit, so it is the biggest lever on motion clarity. 60Hz holds each frame for 16.7ms, 144Hz for 6.94ms and 240Hz for 4.17ms. The table runs the worked example across four rates:
| Refresh rate | Hold per refresh | Blur width (worked example) |
|---|---|---|
| 60Hz | 16.67 ms | 22.0 px |
| 100Hz | 10.00 ms | 13.2 px |
| 165Hz | 6.06 ms | 8.0 px |
| 280Hz | 3.57 ms | 4.7 px |
Halving the hold halves the blur, which is why moving from 60Hz to 144Hz feels dramatic, while 240Hz over 144Hz is a smaller high refresh gain you mostly notice in esports flicks. Frame rate still limits you: a 30 FPS game on a 165Hz screen keeps the visible stepping of 30 FPS, because each image repeats for several refreshes. A motion clarity test only predicts competitive gaming results when your GPU holds 165 fps, as in a first-person shooter.
Frame Time and Frame Rate Limits
Frame time is the gap between refreshes, and the frame interval should stay steady. Spikes mean dropped frames, which show up as stutter: the object jumps instead of gliding, and any blur reading becomes meaningless.
VRR, G-Sync and FreeSync Effects
Variable refresh rate technologies such as G-Sync and FreeSync remove screen tearing and input lag, but not hold blur: 120 fps on an adaptive-sync display blurs like a fixed 120Hz refresh. While testing, disable VRR and lock the frame rate to the refresh, never a 60 FPS game on a faster display, so each hold matches the formula.
Tuning Overdrive and Strobing to Cut Trailing
Once you know which kind of trailing you see, two hardware settings on most gaming monitor models change it: overdrive for response and a strobed backlight for hold. Laptop panels and TV sets usually expose only the first, if any.
Picking the Right Overdrive Level in the OSD Menu
Overdrive levels typically run Off, Low, Medium, Fast and Extreme (some brands say Normal or High). Step through them with the test pattern unchanged, and repeat at each refresh rate you use:
- Off or the weakest step: a long dark trail of ghosting behind the object.
- A balanced middle step: crisp, sharp edges and the shortest streak.
- The strongest step: bright halos returning around the object.
Keep the strongest setting before a bright fringe appears, set in the on-screen display (OSD).
Backlight Strobing and Motion Blur Reduction
Backlight strobing flashes the backlight once per refresh and keeps it dark in between, so each image is seen for a brief pulse instead of the whole refresh. Branded as ULMB, DyAc or ELMB, this motion blur reduction can cut MPRT close to 1 ms. With a 1.5 ms pulse, the worked example shrinks from 8 px to about 2 px. Expect a dimmer picture and some flicker.
Panel Technology: OLED, IPS and TN
OLED and QD-OLED pixels switch in well under 1 ms, so their blur is almost pure MPRT and follows refresh rate directly. Fast IPS panels reach a few ms of GtG with tidy overdrive, TN still offers quick panel response with weaker viewing angles, and VA trades response for contrast. Your best display quality for motion comes from matching the panel to how you play.
Frequently Asked Questions
- What causes motion blur on a monitor?
- Two things add up. Sample-and-hold persistence keeps each frame lit for a full refresh while your eyes keep moving, which smears the image across your retina, and slow pixel transitions (GtG) add a trail behind moving objects. On most modern screens, persistence is the larger part.
- Can a browser test measure my monitor's exact response time?
- No. A browser can time frames and move objects at a known speed, but measuring true GtG or MPRT needs a photodiode or a high-speed camera. Use the test to compare settings and spot artifacts, and treat the MPRT figure as an estimate.
- What is the difference between GtG and MPRT?
- GtG (gray-to-gray) is how long a pixel takes to change from one shade to another. MPRT (moving picture response time) is how long each image stays visible, which is what your eyes perceive as motion blur. A 1ms GtG panel running at 60Hz still has about 16.7 ms of persistence.
- What is inverse ghosting?
- Inverse ghosting is a bright or dark halo ahead of or behind a moving object, caused by overdrive pushing pixels past their target color. Lowering the overdrive setting by one level in the monitor's OSD menu usually removes it.
- Why does my 1ms monitor still show ghosting?
- Advertised response times are measured on the fastest color transitions under ideal settings. Real transitions, especially dark ones on VA panels, are often slower, and the overdrive level you pick changes the result.
- Which overdrive setting should I use?
- Run the test at one speed and step through every overdrive level. Keep the strongest setting that shortens the trail without adding a bright edge or halo, and repeat at each refresh rate you use, since the best level can change with refresh rate.
- Why does my 144Hz monitor look like 60Hz in the test?
- The display is often still set to 60Hz in Windows or macOS settings, the cable cannot carry the higher rate, hardware acceleration is off in the browser, or a laptop is in power-saving mode. Fix the refresh rate first, then rerun the test.