Dead Pixel Test
Find dead or stuck pixels with fullscreen solid colors and gradients.
Flood your screen with pure colors to hunt down dead (always black) and stuck (always lit) pixels — then try to revive a stuck one. Best viewed fullscreen, with the screen cleaned first.
⚠️ Flashing-light warning
This test flashes rapidly (6–30 Hz) to exercise a stuck pixel. Do not use it if you — or anyone who can see the screen — have photosensitive epilepsy or are sensitive to flashing lights. The flash starts confined to a small draggable square; you can switch to whole-screen from the control bar if you need to.
How to read it
- Dead pixel — stays black on white & bright colors. Usually unfixable.
- Stuck pixel — shows the wrong color (a bright dot) on solid backgrounds. The flash test can sometimes free it.
- Look from ~30 cm away. A clean screen avoids mistaking dust for pixels.
- For a stuck pixel, run the flash test over it for a few minutes (you can also gently massage the spot with a soft cloth).
Controls once open: tap / Space next · ←→ cycle · F fullscreen · Esc exit.
Why you’ll love Dead Pixel Test
Instant & free
No signup, no paywall, no limits — Dead Pixel Test works the moment the page loads.
Completely private
Everything runs in your browser. Nothing you enter is ever uploaded or stored on a server.
Works on any device
Fully responsive and touch-friendly — use it on your phone, tablet or desktop.
Uses your real device
Taps into your actual camera, mic or motion sensors — right in the browser.
How to use it
Open it
No download and no login — the tool is ready right at the top of this page.
Use it
Enter your details or start interacting. Everything updates live as you go.
Get your result
Copy, download or share your result in a single tap. That’s it.
About Dead Pixel Test
Every pixel on an LCD or OLED screen is built from red, green and blue subpixels. When one of them fails, it either stays permanently black (a dead pixel) or permanently lit in one colour (a stuck pixel). Defects like these hide easily on a busy desktop, which is why this test floods your entire screen with pure solid colours — red, green, blue, white, black, gray, cyan, magenta and yellow. A dead pixel shows up as a black dot on every bright colour; a stuck pixel appears as a wrongly-coloured dot on solid backgrounds.
Beyond single pixels, the gradient screens reveal panel-level problems: smooth RGB and grayscale sweeps expose colour banding, a full-hue sweep shows tint shifts, and the checkerboard and pixel-grid patterns make uneven sharpness or scaling artifacts obvious. Sit about 30 cm from a clean screen — a speck of dust is the most common false alarm.
If you find a stuck (not dead) pixel, the built-in exerciser rapidly flashes black and white at 6 to 30 Hz over a small draggable spot or the whole screen. Cycling a stuck subpixel this way for a few minutes can sometimes free it; truly dead pixels are usually permanent hardware faults. A photosensitivity warning is shown before any flashing starts. The whole test runs in your browser with real fullscreen, keyboard shortcuts and tap-to-cycle controls — nothing to download or install.
Popular uses
Frequently asked questions
A dead pixel receives no power and stays black on every colour, so it is easiest to spot on the white screen. A stuck pixel has one or more subpixels frozen "on", so it glows red, green, blue or another fixed colour and stands out on the opposite solid colours (a stuck-red dot is obvious on green or black). Dead pixels are almost never fixable; stuck pixels sometimes recover.
Sometimes. Rapidly alternating black and white forces the liquid-crystal cell and its transistor to switch thousands of times, which can free a subpixel that is stuck rather than dead. Position the flashing spot directly over the pixel and let it run for several minutes — some people also gently massage the spot through a soft cloth. There is no guarantee, but it costs nothing to try and cannot harm a modern panel.
At minimum cycle red, green, blue, white and black. Each pure colour lights only one subpixel type, so a defect in a single subpixel only becomes visible on specific colours: a dead green subpixel looks fine on red and blue screens but shows as a dark dot on green and a magenta-tinted dot on white. White catches fully dead pixels; black catches anything stuck on.
It depends on the manufacturer's pixel policy, usually based on the ISO 9241-307 fault classes. Many brands only replace a panel above a threshold — for example several bright or dark dots — while premium "zero bright dot" warranties replace on a single stuck-bright pixel. Run this test within your return window: retailers' remorse periods are typically far more forgiving than warranty pixel policies.
Browser toolbars and the taskbar cover part of the panel, so a windowed test can miss defects at the edges. This tool requests true fullscreen via the browser Fullscreen API so every pixel of the panel is painted; if your browser blocks it, the test falls back to a full-viewport overlay and you can press F to retry fullscreen.
Dead Pixel Test is 100% free — no signup, no watermarks and no usage limits. It’s one of 200+ free tools we build and give away.
No. All sensor data is processed live on your device and never leaves it or gets stored.
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