Monitor Ghosting Test
Follow the moving objects with your eyes to see how cleanly your screen handles motion. Trails behind them are ghosting, bright or dark halos are overdrive overshoot, and the frame-rate lanes show how refresh rate changes motion clarity. Your refresh rate is detected automatically.
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Keys: Space pause, ← → speed, O object, B background, F full screen, Esc exit.
How to use the Monitor Ghosting Test
- Set browser zoom to 100% and use your monitor's native resolution and highest refresh rate.
- Choose a speed (960 px/s is a good start), an object and a lane layout.
- Follow one object with your eyes as it crosses the screen. Look at its trailing edge for faint copies (ghosting) and bright or dark outlines (overshoot).
- Compare backgrounds: ghosting is often worst on dark backgrounds, overshoot on mid-gray.
- Change your monitor's overdrive setting (also called response time, trace free or OD), then watch again and keep the setting with the cleanest edges.
What to look for
| What you see | Cause | What to try |
|---|---|---|
| Faint copies or a dark smear trailing the object | Ghosting: slow pixel transitions | Raise overdrive one step; VA panels often smear most on dark backgrounds |
| Bright, white or colored outline behind the object | Overshoot (inverse ghosting) from too much overdrive | Lower overdrive one step |
| Evenly blurred edges, no distinct trail | Persistence blur of sample-and-hold displays | Higher refresh rate, or backlight strobing / motion blur reduction |
| Object jumps or stutters | Dropped frames or uneven frame pacing | Close background apps, enable hardware acceleration, check refresh rate |
| Several sharp copies of the object | Low frame rate (see the 1/2 and 1/4 lanes) or strobing at a lower rate than the content | Match frame rate and refresh rate |
Motion blur by refresh rate
On a sample-and-hold screen, an object you follow with your eyes is smeared by roughly the distance it moves during one frame: blur width (px) ≈ speed (px/s) ÷ refresh rate (Hz). At 960 px/s:
| Refresh rate | Frame time | Movement per frame at 960 px/s |
|---|---|---|
| 60 Hz | 16.7 ms | 16 px |
| 120 Hz | 8.3 ms | 8 px |
| 144 Hz | 6.9 ms | 6.7 px (the test rounds to 7) |
| 240 Hz | 4.2 ms | 4 px |
| 360 Hz | 2.8 ms | 2.7 px (the test rounds to 3) |
Slow pixel response adds ghosting on top of this persistence blur. The test always moves objects by a whole number of pixels per frame, so the speed shown may differ slightly from the one you picked.
Getting a fair result
- Keep browser zoom at 100% and the window on the monitor you are testing.
- Track the object with your eyes instead of staring at a fixed point; fixed-gaze viewing hides ghosting behind the natural motion blur.
- Try each overdrive level for a minute; the best level is usually the one where trails are short and no bright halos appear.
- Variable refresh rate (G-Sync, FreeSync) can change overdrive behavior at lower frame rates, so test the frame-rate lanes too.
Frequently asked questions
What is monitor ghosting?
Ghosting is a faint trail behind moving objects caused by pixels that change color too slowly. Each frame, part of the previous image is still visible while the pixels finish their transition. It is most common on VA panels and on dark-to-gray transitions, and is reduced by faster panels and the monitor's overdrive setting.
What is inverse ghosting or overshoot?
Overdrive speeds up pixel transitions by briefly pushing a higher voltage. If it is set too strong, pixels overshoot their target and you see a bright or colored halo (or a dark one) behind moving objects. That is inverse ghosting. Choose the strongest overdrive level that does not produce visible halos, often the middle setting.
Why do moving objects look blurry even without ghosting?
Most LCD and OLED screens are sample-and-hold displays: each frame stays lit for the full refresh period while your eyes keep moving, which smears the image on your retina. This persistence blur depends on frame time, not pixel speed, so it halves when the refresh rate doubles. Backlight strobing modes (often called ULMB, ELMB or motion blur reduction) reduce it further.
Why does the test say frames were dropped?
The browser missed one or more refreshes, so objects jumped and motion looked jerky. Close other tabs, plug in a laptop, make sure the window is on the high-refresh monitor and that hardware acceleration is enabled in the browser. Variable refresh rate and some power saving modes can also cause irregular frame pacing.
Why is my refresh rate shown as 60 Hz on a 144 Hz monitor?
The browser draws at the refresh rate the operating system uses for that display. Check the display settings in Windows or macOS and the refresh rate in your graphics driver, use a DisplayPort or suitable HDMI cable, and make sure the browser window is on that monitor. Some laptops lower the refresh rate on battery power.
What speed should I use?
960 pixels per second is a common reference speed that makes ghosting easy to see on most screens. Slower speeds help judge fine detail; faster speeds exaggerate trails and blur. The test moves objects by a whole number of pixels each frame, so motion stays perfectly even.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.