Testbench

Dead pixel test — pick a colour, then go full screen

Screen—px
Window—px
Pixel ratio—×
Colour depth—bit
Solid colours
Patterns
Stuck-pixel flasher

The flasher shows rapidly changing colours. Don't use it if you're sensitive to flashing light.

Rear panel

PIXELS Dead pixel test

Measures
Full-screen colours, gradients, stuck-pixel flasher
Browser API
Fullscreen API · screen · devicePixelRatio
Known quirks
Safari on iPhone has no full-screen mode for pages, so the test fills the browser window instead.

Operating procedure

Press Full screen, then click or press the arrow keys to step through solid colours. A dead pixel stays black on every colour; a stuck pixel stays one bright colour.

  1. Clean the screen first: dust looks exactly like a dead pixel. Set brightness to normal.
  2. Press Full screen. Click, tap or press → to step through the colours, ← to go back, Esc to leave.
  3. On black, look for bright dots (stuck pixels). On white, red, green and blue, look for black dots (dead pixels) or dots of the wrong colour.
  4. Use Bleed in a dark room to check the edges for backlight bleed or IPS glow, and the grey ramp to see banding or uneven areas.
  5. Found a stuck pixel? Try the flasher on that spot for 10–20 minutes. It sometimes frees it; it can't revive a truly dead pixel.

Fault codes

  1. PIX-E1

    Is it dead or stuck?

    Fix A dead pixel is black on every colour: no power reaches it, and it's rarely fixable. A stuck pixel shows one colour (red, green, blue or white) all the time; it's a sub-pixel stuck on and can sometimes be revived with the flasher or gentle pressure through a soft cloth.

  2. PIX-E2

    Full screen doesn't cover the whole display

    Fix On iPhone, Safari doesn't allow full screen for web pages; the test fills the window instead. Rotate to landscape and scroll so the address bar shrinks. On desktop, make sure browser zoom is 100%.

  3. PIX-E3

    I see a dot that moves when I scroll

    Fix Then it's in the image or on the surface, not in the panel. Clean the screen with a microfibre cloth.

  4. PIX-E4

    Bright patches at the edges on black

    Fix That's backlight bleed or IPS glow, common on LCD panels. Glow changes with viewing angle; bleed doesn't. Lowering brightness reduces both.

  5. PIX-E5

    When can I return a monitor for dead pixels?

    Fix It depends on the manufacturer's pixel policy (often based on ISO 9241-307 classes) and the store's return window. Test new screens straight away and take a photo of the defect on a solid colour.

Service notes

How do I check my screen for dead pixels?
Clean the screen, open the full-screen test and step through black, white, red, green and blue. Look closely over the whole surface on each colour. A dot that stays black or one colour across tests is a faulty pixel.
Can a stuck pixel be fixed?
Sometimes. Running the flasher over the pixel for 10–20 minutes rapidly switches it on and off, which can free a stuck sub-pixel. Dead pixels (black on every colour) usually can't be fixed.
Is the flasher safe?
It's safe for the screen. It flashes quickly, so people with photosensitive epilepsy shouldn't look at it. The page asks for confirmation and starts nothing automatically.
Does this work on phones and TVs?
Yes. On Android and most smart-TV browsers full screen works. On iPhone, the test fills the browser window.
How many dead pixels are acceptable?
That's set by each manufacturer's warranty policy. Many accept zero bright pixels on premium models but allow a few dark ones. Check your model's policy page.