Dead & stuck pixels
Nine pure colors, edge to edge. A dead pixel stays black, a stuck one stays lit.
1 minGuide
Monitor Ghosting Test
Moving objects at set speeds, stepped in sync with your refresh rate. 100% in your browser - nothing is uploaded.
1 min2 patterns
Click the preview to run it full screen
Your display
Updates when you move the window to another screen- Resolution
- ---
- device px
- Pixel ratio
- ---
- devicePixelRatio
- Refresh rate
- ---
- measured in this browser
- Color gamut
- ---
- reported by the browser
- HDR
- ---
- standard range
- Orientation
- ---
- current
How to run the monitor ghosting test
01Highest refresh rate
Set the monitor to its top rate and check the Hz reading in the test controls.
02Follow the objects
Start the test and track one moving object with your eyes, not the screen center.
03Try faster speeds
Start at the default, then the faster presets. The controls show the jump per frame.
04Compare overdrive
Change the monitor’s overdrive setting between runs and compare the trails.
What to look for
- A dark or blurred trail behind the object: slow response, classic ghosting.
- A bright, inverted or colored halo: overshoot from overdrive set too strong.
- Differences between lanes: dark-lane smearing is typical for VA panels.
What counts as a defect
- Strong trails at the monitor’s advertised refresh rate, with overdrive on its recommended setting, are a sign of a slow panel.
- Visible overshoot on every overdrive setting suggests poor tuning for that refresh rate.
- Some blur is normal on every sample-and-hold display. Compare with reviews of the same panel type.
What to do next
- Pick the overdrive level with the least overshoot that still looks sharp, usually the middle one.
- If a motion blur reduction mode exists (backlight strobing), try it: it trades brightness for clarity.
- Low Hz reading? Confirm it with the refresh rate test, then check the OS setting and that the cable supports the rate.
Other screen tests
Each one checks a different part of the panel. The guided check runs them all in order.
Uniformity & clouding
Flat greys and white show clouding, dirty-screen effect and tinted zones.
1 minGuide
Banding & gradients
256 equal steps per ramp. A good panel shows them evenly, a weak one clumps them.
1 minGuide
Sharpness & geometry
One-pixel grids, checkerboards and circles expose scaling blur and bad geometry.
1 minGuide
Refresh rate & tearing
Measures the real frame rate in this browser and shows tearing on a moving bar.
30 sGuide
About the monitor ghosting test
When pixels change too slowly, a moving object leaves a trail; when overdrive pushes them too hard, it leaves a bright or colored halo instead. Objects move across three lanes of different brightness, because transitions from dark and to dark behave very differently. The step per frame comes from your measured refresh rate, so any judder you see is not the test’s.
It is one of the tests in the Screen & Monitor Test, which also runs a guided check through every test and ends in an inspection reportfor a return or RMA. Every pattern is drawn on your screen's own pixel grid, 100% in your browser - no upload, no install, no account needed.
Frequently Asked Questions
Ghosting is a visible trail caused by pixels not finishing their transition in time. Motion blur also comes from your eyes tracking an object while each frame stays lit for its whole duration (sample and hold). Faster pixels reduce ghosting; higher refresh rates and backlight strobing reduce blur.
Overdrive speeds pixels up by briefly driving them past their target. If it is set too strong, they overshoot and leave a bright or colored halo, which looks like a trail with inverted colors. Lower the overdrive setting to reduce it.
Trails depend on how far the object jumps between frames on the panel. Device pixels per second, divided by the refresh rate, gives exactly that distance, and the controls show it as px per frame.
Safari on iPhone does not allow web pages to go truly full screen. The test fills the whole visible area and hides all controls instead; rotate to landscape, or add the page to your Home Screen, to get the most of the panel in view. iPad and Android support real full screen.
No. Every pattern is drawn locally in your browser, and the inspection report is built and downloaded on your device. Nothing about your screen or your results leaves the browser, and no account is needed.
From the blog
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See what monitor ghosting and inverse ghosting look like, test motion in a browser, and use the results to tune overdrive without mistaking refresh rate for response time.
Read →monitorHow to Test a New or Used Monitor Before the Return Window Closes
A practical monitor inspection checklist for finding dead pixels, uneven backlighting, banding, ghosting, and other panel issues before you keep or buy a display.
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