Dead Pixel Test — Find Stuck Pixels

A full screen color cycle to find dead and stuck pixels, plus optional flashing

Runs in your browser · nothing is uploaded

Screen color test

The whole screen steps through black, white, red, green, blue, gray and a custom color. Look closely for any dot that is a different color.

Color for the last stepShow the hint while testing

Tap, click, Space or → next · ← back · Esc or the Exit button to exit

Pixel fix flashing (optional)

Photosensitivity warning

Rapidly flashing screens can trigger seizures in people with photosensitive epilepsy. Do not use this if you have a history of seizures, or if you feel dizzy, get a headache or your eyes hurt. Once flashing starts, Esc, Space or the Exit button stops it at once, and it stops by itself after 10 minutes. It never starts automatically.

Flashing is reported to free a stuck pixel (one frozen on a single color) in some cases, but it is not guaranteed. A dead pixel (always black) usually cannot be revived. If nothing helps, check the manufacturer warranty and its bad pixel policy. Long sessions can stress the panel, so keep it short.

Speed (color changes per second)

Flashing area

I have read the warning and understand the risk

A stuck pixel stays lit in one color such as red, green or blue. A dead pixel is always off and looks black. Look for black dots on white and bright dots on black.

This tool only paints colors on your screen and stores or sends nothing.

What it is

The Dead Pixel Test fills the whole display of a monitor, laptop or phone with a single color to reveal dead pixels, which are always off, and stuck pixels, which are frozen on one color. Use it when a new screen arrives, while the return window is still open, or before buying a used one. It walks through seven plain colors, and there is an optional flashing mode that is sometimes used to try to free a stuck pixel.

How to use

Clean the screen, dim the room and set the brightness to what you normally use.
Press Start full screen test. The screen begins with black.
Click, press Space or the right arrow to go to the next color, and the left arrow to go back. The order is black, white, red, green, blue, gray and finally the custom color you picked.
On each color, lean in and scan every edge and corner. Look for black dots on white, bright dots on black, and off-color dots on red, green and blue.
Press Esc or the Exit button at the bottom to leave. On a phone or tablet, each tap moves to the next color and shows the Exit button for a few seconds. The hint fades after a few seconds and returns when you move the mouse. The cursor hides together with the hint. With the hint turned off, the Exit button still appears after a tap or mouse move.
If you find a dot, note its position and the colors on which it shows. That helps when you ask for a replacement.

How it works

Dead pixel: always off, so it looks black on white and on colors. Most cannot be revived.
Stuck pixel: lit all the time. It appears as a red, green, blue or white dot on a black screen. Some are reported to loosen after flashing.
Telling dust apart: dust or smudges on the glass wipe off and seem to shift when you change your angle. A pixel stays in the same spot after wiping.
Pixel fix flashing: cycles red, green, blue, white and black. You can pick 2, 5 or 10 color changes per second, and 2 is the default. Five and ten exceed the three flashes per second limit recommended by web accessibility guidelines, so they carry a risk label. If your device has reduce motion turned on, only the slowest speed is allowed.
Small window mode: only a 240 px square flashes and the rest stays black. Drag it or move it with the arrow keys over the problem pixel.
Safeguards: flashing needs the warning checkbox, stops instantly with Esc, Space or the Exit button, and stops by itself after 10 minutes.

Examples

What you see	Likely cause
A tiny black dot on white and on colors	Dead pixel
One spot glowing red on a black screen	Stuck pixel
A dot that wipes away	Dust or a smudge
A dark dot only on the blue screen	Faulty blue subpixel
Soft glow along the screen edges	Backlight bleed, which is not a pixel defect

Do not touch the panel while testing, and look from a steady distance. A dot inside the manufacturer’s allowed range may not qualify for replacement, so check the policy before you buy.

FAQ

What is the difference between a dead pixel and a stuck pixel?

A dead pixel is always off, so it shows as a black dot on every color. A stuck pixel stays lit in one color such as red, green or blue, so it shows as a bright dot on a black screen. That is why you look for black dots on white and bright dots on black, and for off-color dots on the red, green and blue screens.

Will a few bad pixels qualify for a replacement?

It depends on the maker and the model. Many manufacturers decide by the number of bad pixels and where they are, with stricter limits near the center of the screen, so read the seller's or manufacturer's bad pixel policy first. This tool shows whether a dot exists and does not judge whether it qualifies.

Is the pixel fix flashing safe?

Rapid flashing can trigger seizures in people with photosensitive epilepsy, so do not use it if that applies to you. It never starts by itself, and you must tick a box confirming you read the warning. The default speed is two color changes per second, Esc or Space stops it at any moment, and it stops on its own after 10 minutes. Results are not guaranteed.

Full screen does not work for me.

If the browser refuses the full screen request, the tool covers the whole window instead. The address bar may still show, so press F11 to put the browser itself in full screen and check the edges too.

Does this tool store anything about me?

No. It only paints colors on your screen and stores or sends no information.