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

A dead pixel stays black on every colour because it receives no power, while a stuck pixel is locked on one colour, so it shows as a bright red, green or blue dot against the others. Stuck pixels sometimes recover by themselves or with gentle pressure or pixel-cycling tools; dead pixels usually do not.

How do I find a stuck pixel?

Fill the screen with each solid colour in turn and look closely. A stuck pixel appears as a tiny dot of the wrong colour: most obvious on the black screen if it is stuck bright, or on a solid colour if it is stuck off. Cleaning the screen first avoids mistaking dust for a fault.

My phone or TV — can I test those too?

Yes. The patterns fill whatever screen the browser is on, so they work on phones, tablets, laptops, external monitors and most smart TVs with a browser. For a TV or projector, the gradient and sharpness patterns are especially useful for spotting banding and focus issues.

Is my camera, microphone or data sent anywhere?

No. Every test runs locally in your browser on your own device. When a test needs your camera or microphone, the feed is shown to you and nothing else: it is never uploaded, never recorded to a server, and never stored. Close the tab and it is gone. You can confirm it by disconnecting from the internet after the page loads; the tests still work.

Monitor & Dead Pixel Test

Check your screen for dead and stuck pixels and other faults. Fill the display with solid red, green, blue, white and black in turn, so a pixel that is the wrong colour stands out at once. Gradient and sharpness patterns reveal banding and focus problems. Works on any monitor, phone or TV.

No app to install
100% free
Nothing is recorded
No sign-up, no email
Works on any device

Read the guide: How to Test for Dead Pixels

Pick a pattern to go full screen

Once full screen, click or press the arrow keys to change colour. Press Esc to exit. Scan each solid colour for any dot that is the wrong shade.

How to use it

1
Go full screen

Open a colour and let it fill the whole display. Clear other windows so nothing distracts from the test pattern.
2
Cycle the colours

Step through red, green, blue, white and black. On each, scan the screen for any dot that is not the expected colour.
3
Check gradients and sharpness

Use the gradient to spot banding and the sharpness grid to judge focus and geometry, especially on a projector or TV.

When it comes in handy

Buying a new or used screen

Run the colours before the return window closes, so you catch a dead pixel while you can still exchange it.

Stuck pixel hunting

Tell a dead pixel (always black) from a stuck one (locked on a colour), which sometimes recovers on its own.

Calibration and setup

Use the gradient and sharpness patterns to check banding, backlight bleed and focus when setting up a display.

Instant & 100% private — nothing is recorded

The test runs right here in your browser. When it needs your camera or microphone, the feed is shown to you and nothing else: never uploaded, never recorded to a server, never stored. There is no sign-up and no email wall, and most tests keep working with no connection at all.

Frequently asked questions

What is the difference between a dead pixel and a stuck pixel?: A dead pixel stays black on every colour because it receives no power, while a stuck pixel is locked on one colour, so it shows as a bright red, green or blue dot against the others. Stuck pixels sometimes recover by themselves or with gentle pressure or pixel-cycling tools; dead pixels usually do not.
How do I find a stuck pixel?: Fill the screen with each solid colour in turn and look closely. A stuck pixel appears as a tiny dot of the wrong colour: most obvious on the black screen if it is stuck bright, or on a solid colour if it is stuck off. Cleaning the screen first avoids mistaking dust for a fault.
My phone or TV — can I test those too?: Yes. The patterns fill whatever screen the browser is on, so they work on phones, tablets, laptops, external monitors and most smart TVs with a browser. For a TV or projector, the gradient and sharpness patterns are especially useful for spotting banding and focus issues.
Is my camera, microphone or data sent anywhere?: No. Every test runs locally in your browser on your own device. When a test needs your camera or microphone, the feed is shown to you and nothing else: it is never uploaded, never recorded to a server, and never stored. Close the tab and it is gone. You can confirm it by disconnecting from the internet after the page loads; the tests still work.