Dead Pixel Test
Cycle fullscreen solid colors (red, green, blue, white, black and more) to find dead or stuck pixels on any monitor or phone.
Last reviewed by the Radiatus Cloud team
Click “Start test” to go fullscreen, then click / press any key (or →) to cycle through solid colors. Inspect the screen for pixels that stay dark (dead) or show the wrong color (stuck). Press Esc to exit.
Tips: clean the screen first (dust looks like dead pixels); a stuck pixel shows one color on every background, a dead pixel stays black on white. Stuck pixels can sometimes be revived by gently massaging the spot or using rapid color cycling.
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Find dead pixels on a screen
A dead or stuck pixel is a tiny screen fault that is easy to miss, and testing with solid colours reveals them. This tool cycles fullscreen solid colours, red, green, blue, white, black and more, to spot dead pixels.
Why solid colours reveal pixel faults
A dead pixel stays black and a stuck pixel stays one colour, and against a normal image they are almost impossible to notice, but against a fullscreen solid colour they stand out sharply, a black dot on a white screen, a coloured dot on black. Cycling through solid red, green, blue, white and black exercises every subpixel, so a fault in any colour channel shows against the background where it fails to change. This is the standard way to check a screen, useful for inspecting a new monitor or diagnosing a suspected fault before it bothers you daily.
Inspect your display
It runs entirely in your browser, so nothing you enter is uploaded and it works without an account, keeping your data on your own machine.
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Frequently Asked Questions
How does the test reveal dead pixels?
By showing fullscreen solid colours, against which a dead pixel (stuck black) or stuck pixel (stuck one colour) stands out sharply where it fails to match.
Why cycle through several colours?
Because a fault may affect one colour channel, so solid red, green, blue, white and black exercise every subpixel to reveal a fault in any of them.
What is the difference between dead and stuck pixels?
A dead pixel stays black; a stuck pixel stays lit in one colour. Both show against solid backgrounds where the rest of the screen changes.
When should I test?
When inspecting a new monitor or laptop, or diagnosing a suspected screen fault, ideally while a return is still possible.
Is anything uploaded?
No. The test runs entirely in your browser.
Privacy & Security
Runs entirely in your browser. No data is sent to any server.
How to Use
Click Start to go fullscreen, then click or use arrow keys to cycle colors while inspecting the screen. Press Esc to exit.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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UtilityParse a User-Agent string into browser, engine, operating system and device. Explains why UA strings are unreliable and what to use instead.
QR Code Generator
UtilityGenerate QR codes for URLs, text, Wi-Fi and contact details. Adjustable error correction and size, produced entirely in your browser.
Credit Card Validator
UtilityValidate a card number with the Luhn algorithm and identify the issuing network from its prefix. Runs locally, nothing is transmitted.