Fill your screen with solid colours to make dead, stuck and dust-covered pixels obvious. Works on monitors, laptops, phones and televisions.
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The stuck pixel fixer flashes rapidly changing colours in a small area. Avoid it if you
are sensitive to flashing lights or have photosensitive epilepsy.
White Click or press → for the next colour · Escape to exit
How to check your screen properly
- Clean the screen first with a dry microfibre cloth — most "dead pixels" are dust.
- Turn the room lights down. Defects are far easier to see in a dark room.
- Start with black and look for any dot that glows.
- Switch to white and look for any dot that stays dark.
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Work through red, green and blue. A sub-pixel fault only shows on its own colour, so a
pixel that looks fine on white can still fail on red.
- Look at the whole panel including the corners, and view it straight on rather than at an angle.
What you are looking for
- Dead pixel — permanently black. Visible against white and every bright
colour. Caused by a transistor that no longer receives power, and not repairable in
software.
- Stuck pixel — permanently lit in one colour, usually red, green or blue.
Most obvious on a black screen. Sometimes recoverable.
- Hot pixel — permanently white. Shows against black, and is effectively a
stuck pixel with all three sub-pixels on.
- Dust or a mark on the surface — moves or changes with the viewing angle,
and wipes away. Not a pixel defect at all.
Trying to fix a stuck pixel
Software fixers work by cycling the colours of the affected area very quickly, on the theory
that this can free a transistor that has settled into one state. Open the fixer, drag it
over the stuck pixel, and leave it running for ten to thirty minutes. Repeat a few times
before giving up.
Gentle pressure is sometimes suggested as an alternative: with the screen off, press a soft
cloth against the exact spot, then turn the screen on while releasing. Be careful — pressing
too hard damages the panel permanently and creates a much larger fault than the one you
started with. Neither method does anything for a dead pixel, since there is no power
reaching it.
Before you buy or return a screen
Run this test as soon as a new monitor or laptop arrives. Return windows are usually far
more generous than warranty pixel policies, so a defect found in the first two weeks is much
easier to resolve than the same defect found six months later. Photograph anything you find,
with the whole screen in frame so the position of the defect is clear.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A stuck pixel receives power but is frozen on one colour, so it shows as a bright red, green or blue dot and is most visible against black. A dead pixel receives no power at all and stays black, which makes it visible against white. Stuck pixels can sometimes be revived; dead pixels effectively cannot.
How many dead pixels are allowed under warranty?
It depends entirely on the manufacturer and the class of panel. Many warranties tolerate a small number of sub-pixel defects before a screen qualifies for replacement, and the threshold is often stricter for premium models. Check the specific policy for your model before contacting support.
Can a stuck pixel fix itself?
Sometimes. Stuck pixels occasionally clear up on their own after a few days of normal use. Rapid colour cycling of the affected area, which is what the pixel fixer below does, is the usual software attempt at speeding this along. It is not guaranteed and it does nothing for genuinely dead pixels.
I see a dark smudge rather than a single dot.
That is more likely to be pressure damage or a backlight problem than a pixel defect. Dust or fingerprints on the surface look similar too — clean the screen with a dry microfibre cloth first, and check whether the mark moves as you tilt the display.
Does this test work on a phone or a TV?
Yes. Any screen that can open this page in full screen works. For a television, open the page in the built-in browser or cast the tab from a laptop, and view it in a dark room for the clearest result.
Why does the black screen look uneven rather than truly black?
On LCD panels that is backlight bleed or clouding, which is separate from pixel defects. It is most visible along the edges in a dark room. OLED screens do not have this because each pixel is its own light source.