Monitor Ghosting Test
Reveal ghosting, motion blur, and overdrive artifacts with a smooth, time-based motion test. Follow the moving object with your eyes as it sweeps across the screen: faint copies trailing behind it are ghosting from slow pixel response, while bright or dark halos are inverse ghosting from too much overdrive. Adjust speed, background, and rows, and go fullscreen for an edge-to-edge look.
Follow the moving object with your eyes. Faint copies trailing behind it are ghosting; bright or dark halos around it are inverse ghosting from too much overdrive.
Faint trailing copies behind the object. Caused by slow pixel response — the panel can’t finish the color change before the next frame.
Bright or dark halos and reverse trails. A sign of too much overdrive (overshoot) — lower the overdrive setting.
A uniform smear across the whole object, even with instant pixels. This is sample-and-hold persistence and eases at higher refresh rates.
Monitor ghosting is the faint trail or smear that follows a moving object across the screen. It happens when pixels change color too slowly: this pixel response time, quoted as gray-to-gray (GtG) in milliseconds, is how long a pixel takes to finish switching to its new color. If it can’t finish before the next frame is drawn, the old image lingers as a ghost. Response time is separate from refresh rate — the refresh rate sets how often new frames arrive, and slow pixels smear across whichever frames they’re given — but the two interact, since faster refresh leaves each pixel less time to settle.
To use the test, set a comfortable speed and pick a background that contrasts with the object, then follow the moving box with your eyes rather than staring at a fixed point — ghosting is an eye-tracking artifact and only shows clearly when your gaze tracks the motion. Watch the trailing edge: a clean, sharp edge means fast pixel response, while smeared or doubled copies behind it are ghosting. Try white, gray, and black backgrounds, since different color transitions ghost by different amounts.
Overdrive (also called response-time compensation, RTC, or Trace Free) speeds pixels up by briefly overvoltaging them. Set correctly it cuts ghosting; set too aggressively it overshoots the target color, producing inverse ghosting — bright or dark halos and reverse trails around the object. If you see glowing coronas, lower the overdrive setting in your monitor’s menu; if you see soft trailing, raise it. The best level is usually the one just below where overshoot begins, and it often changes with refresh rate.
Response time and ghosting
| Response time (GtG) | Typical panel | What you see |
|---|---|---|
| Under ~1 ms | OLED, fast TN | Essentially no ghosting — crisp edges |
| 1–4 ms | Good IPS | Slight trailing in fast motion |
| 5–8 ms | Typical IPS / VA | Noticeable blur behind moving objects |
| Over ~8 ms | Slow VA | Strong smearing and dark trails |
How to reduce ghosting?
- Tune the overdrive / response-time setting in your monitor’s menu: raise it to cut trailing, but back off as soon as you see bright or dark overshoot halos.
- Match overdrive to your refresh rate — a level that looks clean at 60 Hz can overshoot at 144 Hz, and some monitors adjust it automatically.
- Be cautious with variable refresh rate (FreeSync / G-Sync): a fixed overdrive level can overshoot as the frame rate swings, so pick the mode that stays clean across the VRR range.
- Consider the panel type: TN and modern fast IPS panels generally have quicker response than VA, which can smear on dark transitions; OLED pixels switch almost instantly and effectively eliminate ghosting.
- Remember that some blur is normal persistence, not ghosting — a higher refresh rate or a backlight-strobing / black-frame-insertion mode reduces that motion blur.