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Dead pixel test for any screen

Fill the screen with one colour at a time and look for a dot that doesn’t match. Check a new monitor, laptop or phone while you can still return it.

Full screen · 8 colours · nothing to install

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    They don’t even reach us: your phone or computer does the work. Nothing to delete later.

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How it works

  1. Start the testPress Start the test: the screen goes black, then white, red, green, blue, grey, a gradient and a fine checker.
  2. Look for a dotStep through the colours with Space or the arrows, or tap and swipe on a phone. Mark any dot you see.
  3. Fix it or report itTry the fixer on a coloured dot, or copy the list of marks for the shop.

How to check a monitor for dead pixels

A new laptop, a second-hand monitor, a phone after a fall: one broken pixel hides easily in a busy picture and is hard to unsee once found. A plain colour across the whole screen shows it in seconds.

Running the dead pixel test

  • Wipe the screen first: a speck of dust looks just like a dead pixel.
  • Turn the brightness all the way up and switch off night mode or a blue light filter.
  • Look at each colour from a normal distance, then check the corners and edges up close.
  • Black shows a pixel that stays lit, white one that stays dark, red, green and blue a stuck subpixel.
  • The gradient shows banding and uneven backlight. In a dark room, black also shows backlight bleed at the edges.
  • The 1-pixel checker shows a pixel that doesn’t switch.

Mark what you find

Press M or the crosshair and click the dot. The test notes its position in real screen pixels, the numbers a shop or a warranty form asks for. After the test the marks are listed under the button, and Copy the list puts them into a message.

Stuck pixel vs dead pixel

A stuck pixel stays one colour, often bright red, green or blue, and sometimes comes back after it is flashed for a while. A dead pixel is black on every colour: the transistor behind it has failed, and no program can revive it. Then read the warranty: many makers replace a screen only above a set number of dead pixels.

Using the stuck pixel fixer

The fixer flashes a square of 48, 80 or 128 px through red, green, blue, white and black. Drag it over the stuck pixel and leave it for 10–20 minutes. If an hour doesn’t help, more time won’t. It starts gentle, at three changes a second. The fast mode, twenty a second, runs only after you confirm flashing is safe for you. If you have photosensitive epilepsy, don’t use it.

Free, fast and all yours

  • Free forever

    Every tool is free and will stay free. No trial, no ads, no paid plan.

  • No sign-up, no login

    Open the page and start. No account, no email, no password.

  • Instant

    Nothing to upload and no queue: a video opens in a second, a simple trim saves in seconds.

  • No file size limits

    We set none. A file can be as big as your device can handle.

  • No watermarks, no copyright

    No logo on top and no rights claimed: what you make is 100% yours.

  • Made for phones too

    The same tools on iPhone, Android and a computer, with big buttons and plain words.

Questions