Monitor Motion Blur & Ghosting Test

How to run the test

01Select the refresh rate and response-time or overdrive mode you normally use.
02Enter full screen, follow one moving block with your eyes, and adjust speed gradually.
03Pause when needed, then compare one display setting at a time at the same speed.
04Watch for dark smears, duplicate-looking trails, bright coronas, or instability.

How to read the result

A soft trail can combine pixel response with sample-and-hold eye-tracking blur.
Dark smearing is common in slower dark transitions on some VA panels.
Bright or colored halos behind an edge can indicate excessive overdrive and inverse ghosting.

Interpretation guide

Separate sample-and-hold blur, pixel trails, and overdrive artifacts

Several mechanisms can soften a moving target

On a sample-and-hold display, each frame remains visible until the next refresh. When your eyes track a moving object, that held image spreads across the retina and looks blurred even if pixel transitions are fast. Slow pixel transitions add trailing smears because the pixel has not reached its new value before subsequent frames. Low frame rate, frame-time variation, motion blur rendered by a game, scaling, and persistence-reduction modes add other effects. A moving browser target reveals the combined experience; it does not isolate one response-time number.

Overdrive trades ordinary ghosting for inverse ghosting

LCD overdrive briefly pushes a transition harder so the pixel reaches its target sooner. Too little can leave a same-colored trail behind motion. Too much overshoots the target and produces a bright, dark, or differently colored corona often called inverse ghosting. The best setting can change with refresh rate because the available frame time changes. Test slow, medium, and fast motion at each refresh rate you actually use, including variable-refresh conditions. The highest overdrive label is not automatically the clearest choice.

A browser animation needs a healthy rendering loop

Close busy tabs and applications, keep the test window visible, and wait for the refresh indicator to stabilize. Browsers can drop or repeat animation frames because of scheduling, power management, thermal limits, background throttling, or an unsupported refresh configuration. A page may report a nominal rate while occasional stutter remains. If the motion is uneven, first verify system performance and frame pacing; judging pixel trails during dropped frames mixes two different problems. Compare the same browser, speed, refresh rate, and target when evaluating two settings.

Measurement requires synchronized capture

A pursuit camera moves with the target during exposure so the captured blur approximates tracked-eye motion. A stationary phone photo cannot do this reliably and may add rolling-shutter bands or partial frames. Input lag is also separate from pixel response: response describes how pixels change, while input lag describes delay from an input event to the visible result. Comparing input lag generally requires a synchronized reference or dedicated equipment. Use this page to identify visible trailing and choose settings; do not convert trail length into milliseconds without a validated method.

Reliable visual testing

Build a repeatable test before judging the display

A browser pattern is a controlled visual stimulus, not a measuring instrument. It is excellent for finding visible non-uniformity, clipped tones, scaling errors, halos, color shifts, and motion artifacts under the conditions in which you actually use the screen. It cannot, by itself, report luminance in candelas per square metre, a color difference value, a gamut percentage, or a response-time number. Those claims require a meter, defined test windows, timing equipment, and a documented procedure. Use this page first as a practical screening and comparison tool: it can tell you where to look, whether a change is repeatable, and whether one setting or one display looks better than another.

Treat the entire signal path as part of the experiment. The image passes through the page, browser, operating-system color management, graphics driver, cable or wireless link, monitor input mode, picture preset, and panel before it reaches your eyes. Browser zoom, system scaling, non-native resolution, night-light software, HDR conversion, an ICC profile, dynamic contrast, local dimming, sharpening, noise reduction, and variable refresh can each alter the result. A suspicious pattern therefore does not automatically prove a panel defect. Record the active resolution, refresh rate, browser, picture mode, brightness, contrast, color temperature, HDR state, and any adaptive features so that you can reproduce the observation.

Control the room before comparing results. Allow the display to reach a stable operating state, clean the screen with the method recommended by its manufacturer, and prevent direct reflections from crossing the test area. Use moderate, stable ambient light for general checks. Use a dim room only for near-black, black-uniformity, and blooming observations, because those artifacts are easily hidden by reflections and eye adaptation. Do not judge a dark screen immediately after looking at a bright white page; give your vision a short period to adapt. Keep your normal viewing distance and eye height unless the test specifically asks you to move off-axis.

Run the first pass at the panel's native resolution with browser zoom at 100 percent. Full screen reduces distractions, but it does not cancel operating-system scaling or color processing. Inspect once from your normal position, then move closer only to identify the structure of an artifact. Change one control at a time and repeat the same pattern after every change. If several settings move together, you lose the ability to say which one helped. A useful comparison is A/B/A: observe the baseline, apply one change, then return to the baseline. If the effect disappears and returns with the setting, the relationship is more credible than a single impression.

Look for repeatability across content, positions, and inputs. Rotate or move the pattern when the tool allows it. Test a second browser, input, cable, refresh rate, or computer if the finding matters. A mark that stays in the same physical place on the panel is more likely to be display-related; a mark that follows a browser window or screenshot may originate earlier in the signal chain. Photographing the screen can help document location and severity, but a camera introduces exposure, focus, lens shading, moiré, rolling shutter, tone mapping, and white-balance errors. A photograph is evidence of what the camera captured, not a substitute for a calibrated reading.

A compact pre-test checklist

01Stabilize the display

Let brightness and temperature settle, disable screen savers, and avoid testing while the device is rapidly changing power or thermal state.

02Confirm the signal

Use native resolution, verify the intended refresh rate and RGB range, set browser zoom to 100 percent, and note whether SDR or HDR is active.

03Neutralize temporary processing

Pause night light, automatic brightness, dynamic contrast, content-adaptive brightness, and vendor enhancement modes unless one of them is the feature being tested.

04Control the environment

Remove glare, keep ambient light stable, sit square to the screen, and use a darker room only when the test calls for near-black observation.

05Make one change

Adjust only one setting between runs, return to the original value for confirmation, and write down values instead of relying on memory.

06Repeat before concluding

Reopen the pattern, try representative real content, and check another browser or input when the consequence of a wrong conclusion would be costly.

How to turn an impression into useful evidence

Describe what you see without jumping directly to a diagnosis. Record the pattern, color or tone, screen region, viewing distance, room lighting, time after power-on, and whether the artifact changes with angle or settings. Terms such as “a pale vertical band in the left third on 30–50 percent gray” are more useful than “the panel is bad.” Severity should be tied to normal work: state whether the effect is visible only in a dark test room, during ordinary desktop use, or in real video and games. This makes comparisons between presets, firmware versions, and replacement units much more meaningful.

Escalate the method when the decision requires numbers. Photographers and designers may need a colorimeter or spectrophotometer for white point, gamma, tone response, color accuracy, and uniformity. HDR evaluation needs defined test windows and an instrument that can measure bright highlights and dark levels. Motion measurements need synchronized capture or a validated pursuit-camera method. Warranty decisions should follow the manufacturer's pixel, uniformity, and return policies rather than an unofficial universal threshold. The visual test remains valuable: it identifies the question that a formal measurement needs to answer.

What a visible symptom may mean

Soft trail with the target's own color

This is consistent with slow transitions or low overdrive. Raise overdrive one step and check whether the trail shrinks without creating a new corona.

Bright or dark outline follows motion

Overdrive may be overshooting. Reduce it and repeat at the same refresh rate, because the optimal level can differ between rates.

Double images in a strobing mode

Frame rate and refresh rate may not match, or the backlight pulse may expose more than one image. Verify stable frame pacing and the mode's requirements.

Random jumps rather than a continuous trail

Suspect dropped frames, browser scheduling, or system load before pixel response. Close other work and confirm the active refresh rate.

What this browser test cannot measure

This visual tool does not measure gray-to-gray response time, MPRT, overshoot percentage, input lag, or frame persistence. Browser timing can also vary.

Motion test questions

Does this test measure monitor response time?+

No. It helps you compare visible artifacts, but response-time measurement requires synchronized capture and analysis equipment.

Why does the trail change when I move my eyes?+

Sample-and-hold blur depends on eye tracking. Following the object and staring at a fixed point produce different perceived motion.

Methodology and further reading

TestUFO's ghosting test is designed to reveal motion blur, ghosting, and overdrive artifacts under a stable browser animation. Blur Busters explains ordinary versus inverse ghosting and pursuit-camera capture, while Lagom distinguishes response behavior from input lag and warns about browser frame delivery. This page follows those distinctions without reporting an invented millisecond score.

UFO Ghosting TestTestUFO / Blur Busters

LCD Overdrive ArtifactsBlur Busters

LCD Response-Time TestLagom

MOTION BLUR & GHOSTING TEST

Moving edges expose temporal artifacts