Dead Pixel Test
Fill your screen with solid colours to find dead, stuck and hot pixels on a monitor, TV, laptop or phone. Free, instant, nothing to install.
How to test
- 01Clean the screen first, so dust isn't mistaken for a pixel.
- 02Press Start. The screen fills with one colour; tap, click or press → for the next.
- 03Look slowly across the whole screen on each colour, from about an arm's length and then close up.
- 04Note any dot that stays the wrong colour, and on which backgrounds it shows.
What it finds
Every pixel on an LCD or OLED screen is made of red, green and blue sub-pixels. When one of them fails, it shows up against the right background: a dead pixel stays dark on every colour, a stuck pixel shows one bright colour, and a hot pixel stays white.
Cycling through solid colours makes each kind stand out. A defect that hides against white is obvious against black, and the other way round, so a single colour is never enough.
When to run it
- The day a new monitor, TV, laptop or phone arrives, while you can still return it.
- Before buying a second-hand screen or phone, on the seller's device.
- After a drop, or after something pressed on the panel.
- When you notice a dot that doesn't move with the picture.
Tips for an accurate check
- Turn off night mode and blue-light filters: they tint the colours and can hide a stuck pixel.
- Give each colour a few seconds. Your eyes adjust to the large field, and small defects stand out after a moment.
- Use a magnifier or your phone camera's zoom to check that a suspect dot is in the panel, not on the glass.
- On a TV, test at its native resolution, so scaling doesn't blur a single pixel across several.
What your result means
A black dot on every colour except black
A dead pixel: it gets no power and is off for good.
Software can't revive it. If the screen is new, ask for a replacement within the return window.
A dot that stays red, green or blue
A stuck pixel: one sub-pixel is stuck on.
Try the Stuck Pixel Fixer for 10–20 minutes. It often helps.
A white dot on every colour
A hot pixel: all three sub-pixels are stuck on.
Try the fixer, then claim a replacement if it stays.
A dot that moves when you wipe the screen
Dust or a mark on the glass, not a pixel.
Clean with a dry microfibre cloth.
Nothing on any colour
No pixel defects visible.
Your screen passes. Also check for bleed or burn-in if it's new.
How to fix it
New monitor or TV
- Photograph the pixel on the colour where it shows.
- Check the retailer's return window and the maker's pixel policy: some replace a screen for one bright pixel, others need several.
- Return or exchange before the window closes; a warranty claim later is often harder.
Stuck (coloured) pixel
- Run the Stuck Pixel Fixer over the dot for 10–20 minutes.
- If it's still there, repeat once more, then treat it as permanent.
Questions
What's the difference between a dead and a stuck pixel?
A dead pixel is always black because it gets no power. A stuck pixel shows one colour (red, green or blue) because one sub-pixel is stuck on. Stuck pixels can sometimes be freed; dead ones can't.
Can I fix a dead pixel?
Not with software. A truly dead (black) pixel is a hardware fault in the panel. Stuck pixels are different and sometimes respond to rapid flashing.
Do dead pixels spread?
Usually not. A single dead pixel normally stays a single pixel. A growing cluster points to panel damage, so get it checked.
Does this work on phones and TVs?
Yes. On a phone, turn the brightness up and tap through the colours. On a TV, open this page in the TV's browser or cast the browser tab.
Is anything uploaded?
No. The test runs entirely in your browser. Nothing you see, say or film is sent to us or stored anywhere.