Motion blur test
Response time on a spec sheet is a laboratory number under ideal conditions. What you actually see is a moving object leaving a trail behind it. Three patterns at four speeds will show you how much trail your screen leaves, and whether the overdrive setting is helping or hurting.
The test opens full screen. Space — next · Arrow keys — back and forward · Esc — exit
Your browser blocked full screen. The test still works in this window, but a full-screen view is more reliable — try pressing F11.
Did the moving pattern leave a visible trail behind it?
Running the test
Space cycles through four speeds, from 480 to 1920 pixels per second. Up and down switch between three patterns.
The moving bar is the simplest case. Watch its trailing edge.
The moving text is the practical one. If you cannot read it, that is what scrolling a page or panning a camera looks like on your screen.
The checkerboard is the most revealing, because every edge in it moves at once. Overshoot halos that are invisible on a single bar are obvious here.
Track the object with your eyes as it moves — do not stare at a fixed point. Following the motion is what people actually do, and it is the condition the fault appears under.
Telling the two faults apart
| What trails behind the object | Name | Cause | Fix |
|---|---|---|---|
| Faint copy in the same colour | Ghosting | Pixel transition too slow | Raise overdrive one step |
| Bright white or inverted halo | Overshoot | Overdrive too aggressive | Lower overdrive one step |
| Uniform softness with no distinct trail | Persistence blur | Sample-and-hold display | Higher refresh rate, or strobing mode |
| Trail only on dark transitions | Slow dark-to-light response | Panel characteristic, common on VA | Overdrive helps a little |
| Object appears as several distinct copies | Backlight strobing | The backlight is pulsing | See the flicker test |
VA panels ghost most on dark transitions specifically — a dark object on a dark background is the worst case, and it is the reason VA monitors are criticised for smearing in dark game scenes despite good response times elsewhere.
Finding the right overdrive setting
Manufacturers name this control differently: Overdrive, Response Time, Trace Free, OD, Rampage Response, AMA. It is in the monitor own on-screen menu, not in Windows or macOS.
- Run the checkerboard at the fastest speed.
- Set overdrive to off, and note the trail.
- Step it up one level at a time, watching the same pattern each time.
- Stop at the level just before bright halos appear.
The highest setting is almost never the right one. On most monitors it trades a visible trail for a more visible halo.
Windows 11 and macOS
There is little to set on either, because this is a panel behaviour rather than a software one. Two things still matter:
- Run at the highest refresh rate available. Persistence blur scales directly with frame duration, so 120 Hz halves the blur of 60 Hz before response time enters into it. The refresh rate test earlier in this check tells you whether you are actually there.
- Variable refresh rate changes overdrive behaviour. Many monitors tune overdrive for a single refresh rate, so with G-Sync or FreeSync active and the rate varying, ghosting can appear at some rates and not others. If the trail comes and goes, try a fixed refresh rate to confirm.
Common questions
What is the difference between ghosting and overshoot?
Ghosting is a faint copy of the object trailing behind it in the same colour, caused by pixels not finishing their transition before the next frame. Overshoot, sometimes called inverse ghosting, is a bright or inverted-colour halo, caused by the overdrive circuit pushing pixels too hard past their target value and having to come back. Ghosting means overdrive is too weak; overshoot means it is too strong. They are opposite ends of the same setting.
Why does everything blur even on a fast monitor?
Because of how the display works, not how fast it is. On a sample-and-hold display each frame is held on screen for the whole refresh interval, and your eye tracks the moving object smoothly across it — so the still image smears across your retina. This is persistence blur, and the only real cures are a higher refresh rate or a backlight strobing mode. It is why 240 Hz looks clearer than 60 Hz even when both have the same response time.
Is a browser test accurate enough for this?
For seeing ghosting and overshoot and comparing overdrive settings against each other, yes — those are visible faults and your eye is the instrument that matters. For measuring response time in milliseconds, no. That needs a photodiode and an oscilloscope, and no web page can do it.
Which overdrive setting should I use?
The strongest one that does not produce a visible bright halo. Run the checkerboard pattern at the fastest speed, cycle through the monitor overdrive levels one at a time, and stop at the level just before halos appear. That level is usually the middle option, and it is usually not the one named Extreme.
My laptop screen blurs badly. Can I do anything?
Very little. Laptop panels rarely expose an overdrive setting, and the panel is what it is. What does help is running at the highest refresh rate the panel supports and making sure battery saving is not capping it — both of which reduce persistence blur regardless of response time.