Monitor ghosting test
The target starts moving as soon as the page loads. Follow it with your eyes and look for a trail behind it, the same idea as the UFO test.
Monitor ghosting test workspace
How to use
4 short steps.
Follow the target with your eyes
Keep your head still and track the block as it bounces across the field. Look at the edge that trails behind it.
Change the speed
Start at 960 px/s, the usual reference speed. Try 480 px/s if the trail is hard to see and 1920 px/s on a high refresh rate monitor.
Compare the three backgrounds
Dark-to-light and light-to-dark transitions ghost differently. Check the target on light, gray, and dark.
Go full screen and change overdrive
Click the field for full screen, then change the monitor's overdrive or response time setting one step and watch the trail again.
What the result means
Match what you see to one of these.
If a dark smear follows the target, pixels are changing too slowly
If you see a dark trail behind the block, the panel is not finishing its transitions before the next frame. Raising overdrive by one step usually shortens the trail.
If a bright halo follows the target, overdrive is too high
If the trail is brighter than the background or shows the inverted color, the overdrive is overshooting. Lower it by one step.
If the block is evenly blurred, that is normal sample-and-hold blur
If there is no distinct trail but the block looks soft, you are seeing the persistence blur every LCD and OLED has. A higher refresh rate or a strobing mode reduces it.
If the motion stutters, the source is the problem
If the block jumps rather than glides, the browser or the computer is dropping frames. Close other tabs and check the refresh rate test.
Troubleshooting
If the test fails, try these in order.
Change overdrive one step
Find the overdrive, response time, or trace free setting in the monitor menu. Move it one step and watch the target again at the same speed.
Set the highest refresh rate
In your system display settings, choose the highest refresh rate the monitor supports, then run the target again.
Close other work and disconnect remote desktop
Frame drops look like stutter. Close heavy tabs and apps, then check the refresh rate test to confirm the browser is hitting the full rate.
Try another cable or port
A cable that cannot carry the full refresh rate makes the system fall back to 60 Hz. Swap it and run the ghosting test again.
What this test can't tell you
Where a browser check stops.
- The page cannot measure response time in milliseconds; a trail you can see is real, but its length is not a gray-to-gray number.
- Browser frame timing adds stutter and blur of its own on a busy computer, so judge trails, not smoothness.
FAQ
Common questions about this test.
How do I fix ghosting on my monitor?
Raise the overdrive or response time setting one step in the monitor menu and watch the target again. If a bright halo appears, you went one step too far. Also set the highest refresh rate and use a cable rated for it.
Do IPS monitors have ghosting?
A little. IPS panels are slower than TN and much slower than OLED, so most show a faint trail at 960 px/s unless overdrive is tuned. Modern fast IPS panels with well-tuned overdrive show very little.
What is inverse ghosting?
Inverse ghosting is a bright or color-inverted halo behind a moving object, caused by overdrive pushing pixels past their target. Lower the overdrive setting by one step.
How do I do a UFO ghosting test?
This is the same kind of test. Follow the moving block at 960 px/s and look at what trails behind it on each background. The original UFO test at testufo.com shows several speeds at once.