Dead Pixel Test
Go full screen and step through solid colours to inspect every pixel of your monitor, laptop or phone. Dead, stuck and hot pixels stand out instantly against a flat colour.
Black Look for bright dots (stuck or hot pixels) and for light leaking in from the edges or corners (backlight bleed or IPS glow).
Colours checked: 0 / 9
- Click Space → next colour
- ← previous
- 1–9 pick a colour
- A auto cycle
- Esc exit
Pixel fixer
A small square flashes red, green, blue, white and black very quickly. Drag it over a stuck pixel and leave it running for 10–20 minutes. It sometimes revives stuck pixels; it cannot fix dead ones.
Photosensitivity warning: the pixel fixer shows rapidly flashing colours. Do not use it if you or anyone who can see the screen has photosensitive epilepsy or is sensitive to flashing lights. Do not stare at the flashing square.
The screen will go full screen with a rapidly flashing square. Are you sure you want to continue?
Your device is set to reduce motion. The pixel fixer flashes many times per second. Start it anyway?
How to check a monitor for dead pixels
- Clean the screen. Wipe it gently with a dry microfibre cloth. A speck of dust can look exactly like a dead pixel on white.
- Darken the room. Turn off bright lights and close the blinds, especially when you check the black screen for bright dots and backlight bleed.
- Start the full-screen test. Step through every colour. Look at the screen from your normal viewing distance first, then move closer and scan it slowly, section by section.
- Confirm what you found. If you see a dot, move your head. Dust and reflections move or disappear; a faulty pixel stays in the same spot on the panel. Switch colours to see how it behaves.
Dead, stuck and hot pixels
Every pixel on an LCD screen is made of three subpixels — red, green and blue. Faults show up differently depending on which part has failed:
- Dead pixel — stays black on every colour. Easiest to spot on the white, red, green and blue screens.
- Stuck pixel — one or two subpixels stay on, so you see a coloured dot (often red, green or blue) that does not change with the background. Most visible on black and on the opposite colours.
- Hot pixel — all subpixels stay on, so the pixel is always white. It jumps out on the black screen.
- Partial or dark subpixel — one colour channel is dead. The pixel looks fine on some colours and dark or wrongly coloured on others, which is why the cyan, magenta and yellow screens are included.
Backlight bleed and IPS glow
Use the black screen in a dark room to judge the backlight. Backlight bleed shows up as bright patches along the edges or in the corners that look the same from every angle; it comes from pressure on the panel or a poorly fitted frame. IPS glow is a softer, silvery or warm sheen that changes or fades when you move your head or sit further back, and it is a normal trait of IPS panels. OLED screens have no backlight, so they show neither — on OLED, the black screen should look completely dark.
The 50% gray screen is useful for uniformity: darker corners, blotches or vertical bands are easier to see there than on pure white.
What to do if you find a faulty pixel
Note the colour and the position of the dot and take a photo of it on the test screen. Then check your options:
- Return window. Many shops accept returns for any reason for a short time after purchase. This is often the easiest route, so test a new monitor on the first day.
- Manufacturer pixel policy. Warranties usually only cover pixel faults above a certain number, with different limits for bright and dark pixels and sometimes for their position on the screen. Some premium models promise zero bright pixels.
- ISO 9241-307. Some manufacturers refer to this international standard, which describes pixel fault classes for flat panels. The class defines how many faulty pixels a panel may have and still meet the specification, so a few faults may be considered within spec. Ask the manufacturer which class and limits apply to your model.
Can the pixel fixer help?
The pixel fixer rapidly cycles a small area through red, green, blue, white and black. For a stuck pixel — where a subpixel is stuck on or off — this sometimes gets it working again, and people report results after anything from a few minutes to a few hours. It does not always work, and it cannot repair a dead pixel, because a dead pixel is a physical fault with no working circuit to wake up.
Place the square over the stuck pixel, leave it for 10–20 minutes and check again with the colour test. Avoid pressing or rubbing the screen to fix pixels; it can easily cause more damage than it solves. Once your screen checks out, make sure it also runs at full speed with the refresh rate test.