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Dead pixel test

Fill your screen with black, white, red, green, blue and grey, then ramps, to find dead and stuck pixels. Free, with no account or uploads.

Find dead and stuck pixels

Press Show the colours. Press anywhere for the next colour and look closely; Escape leaves.

The screen fills with black, white, red, green, blue and grey, then two ramps. Press anywhere or the right arrow for the next, the left arrow to go back, and Escape to leave. Clean the screen first: dust looks like a dead pixel.

The rate this browser draws at

Not measured yet

Frames a second
–
Pixels to one CSS pixel
–
  • This is how often this browser draws the page. The screen's own rate can be higher when the browser draws slower: in power saving or low-power mode, on battery, on a second screen, or when the screen's setting is lower than it can go.
  • A screen with a variable rate (ProMotion, FreeSync, G-Sync) may slow down while nothing moves. Keep this page in front while it measures.

These pictures show faults; nothing on a page can repair a stuck or dead pixel.

How it works and help
Everything happens in your browser. Nothing you press is sent anywhere or kept.

A little help along the way

Follow these steps. Every option is explained underneath. Everything happens in your browser; nothing you press is sent anywhere.

  1. Choose your keyboardThe shape (ANSI, ISO, JIS, ABNT2, Korean or Mac) is guessed from your system; change it if it is wrong, and choose the size: full, tenkeyless, 75%, 65%, 60% or the number pad.
  2. Click the board and press your keysEach key lights while held and keeps a tick once it has worked. The site's own shortcuts step aside while you test. Press Escape twice to leave.
  3. Hold several at onceTo test ghosting and rollover, hold many keys together; the result keeps the most held at once.
  4. Read the resultIt says how many keys have worked, which are still to press, the most held at once, and any key that bounced.

Questions people ask

What is the difference between dead and stuck pixels?
A dead pixel stays dark on every colour; a stuck pixel stays lit in one colour, and shows best on black. Both show as a dot that does not change with the rest.
Can a page fix a stuck pixel?
No. The test only shows faults; nothing a page draws can repair a pixel, whatever some sites claim.
What do the ramps show?
Steps or bands in a smooth ramp, from a panel or a setting that shows fewer shades; the grey screen shows patches lighter or darker than the rest.

This page is the Keyboard tester, opened for this one job; every other tool it has is one press away. Each of its settings is explained on the Keyboard tester's own page.

Read the step-by-step guide

Guides

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