Dead Pixel Test for Laptops
Works on any laptop — Windows, MacBook or Chromebook — straight from the browser. Especially worth two minutes before buying or selling a used machine.
Jump to another test
What your browser reports about this display
- Reported size
- —
- CSS pixels
- Pixel ratio
- —
- Scaling factor
- Physical pixels
- —
- Size × ratio
- Viewport
- —
- This window
- Color depth
- —
- Per pixel
These are values the browser exposes, not measurements of the panel. A browser cannot read a display's true native resolution — what that means.
Recommended · 7 patterns · 5s each
Starts with the recommended setup. Nothing to configure.
Advanced timing
Change how long each pattern stays on screen, or turn automatic advance off.
Free · No download · No sign-up · Runs locally in your browser
Power & picture settings first
- •Plug the charger in. On battery, most laptops dim the panel and some drop the refresh rate — both hide faint defects.
- •Turn HDR off while testing. In HDR mode the system tone-maps everything, so a "white" slide is no longer full white.
- • Disable Night Light / True Tone / f.lux — color shifts mask tinted stuck pixels.
- • Open the lid to your usual angle; TN and some IPS panels shift contrast with angle.
- • Wipe the screen — laptop lids collect exactly the dust that impersonates dead pixels.
Is it the panel, or everything before it?
A laptop has a whole pipeline behind its built-in screen. Before you conclude the panel is faulty, plug in an external monitor and run the same test on it.
Only on the built-in screen
Points at the panel or its cable
Dots, bands or bleed that appear on the laptop display but not on the external one are almost certainly the built-in panel — or, for flickering and horizontal lines, the display cable running through the hinge. Hinge-area faults often change when you open and close the lid, which is a useful thing to note in a report.
On both screens
Points at the GPU, driver or settings
A fault that follows you to the external display is not the laptop panel. Check the color depth and scaling settings, update or roll back the graphics driver, and test in a different browser before booking a repair.
Buying or selling a used laptop
A screen defect is one of the few faults you can verify completely in a two-minute meetup: run this test from any browser, no installation required. Check all seven colors — a laptop that looks fine on the desktop wallpaper can hide a cluster of stuck pixels that only shows on black. Sellers benefit too: an exported report dated before shipping is clean evidence of the panel's condition at sale time.
While you're at it, check the hinge-area corners on the backlight bleed test — pressure from a twisted chassis or a tight lid often shows up there first. On touchscreen laptops, finish with the touch grid.
A note on OLED laptops
OLED panels are increasingly common in laptops. They can't have backlight bleed, but they can show banding in dark grays and retain static UI like the taskbar. If your laptop is OLED, follow up with the OLED burn-in test, and remember the taskbar has been in the same place for every hour of the machine's life.
Warranty reality check
Laptop pixel policies tend to be less generous than monitor policies — several defects are often required before a built-in display qualifies. The retailer return window is your strongest tool on a new machine, so test on day one, not day thirty. Details on what counts as fixable: can a dead pixel be fixed?
What this test checks
- Dead, stuck and bright pixels on a built-in laptop display
- Backlight bleed along the edges of a thin panel
- Whether a problem follows the internal screen or an external one
Not sure what you are seeing?
Run diagnosisSave your observations
Create a report