Dead Pixel Test
Fill your whole screen with pure colours to find dead pixels, stuck pixels, backlight bleed and uneven colour on a monitor, laptop, phone or TV. Works in any browser, nothing to install.
Controls: tap / click or → / space = next colour, ← = previous, Esc = exit. Look at each screen from about 30 cm (1 foot) and wipe the screen first, dust looks like a dead pixel.
What to look for
| Screen | Finds |
|---|---|
| White | Dead pixels (black dots), dirt, yellow or dim patches |
| Black | Stuck / hot pixels (bright dots), backlight bleed at the edges |
| Red, green, blue | Sub-pixel faults (a dot missing one colour), colour tint |
| Gradient | Banding, uneven brightness, panel uniformity |
| Checkerboard | Image retention (burn-in) and sharpness, scaling problems |
Questions
How do I test my screen for dead pixels?
Press Start full screen test, then step through the solid colours with the arrow keys or by tapping. Look closely at each screen from about 30 cm (1 foot). A dead pixel is a dot that stays black on bright colours; a stuck pixel is a dot that stays one bright colour (red, green, blue, white) on other screens.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel receives no power and stays black. It is most visible on the white screen. A stuck pixel is always lit in one colour and is most visible on the black screen. A hot pixel is a stuck pixel that is always white. Stuck pixels can sometimes recover; dead pixels usually cannot.
Which colours should I check?
Check white (finds dead pixels), black (finds stuck and hot pixels and backlight bleed), then red, green and blue (find sub-pixel faults). The gradient screen shows banding and uneven colour.
Is a dead pixel covered by warranty?
It depends on the manufacturer's pixel policy, often based on ISO 9241-307 classes. Many brands replace a screen only when a minimum number of defective pixels is reached, or sooner for pixels in the centre. Check the policy and test early, within the return period.
Does this work on phones, TVs and laptops?
Yes. Open this page in the browser of the device (a smart TV browser, phone or laptop) and use full screen. On a phone, tap to change colour. On a TV, use the remote's arrow keys.
Also check your sound and mic: online microphone test · pitch detector.