Dead Pixel Test
Dead pixels show as permanent black dots on any color; stuck pixels glow a single color on black. Sweep through all eight test colors and look for anything that refuses to change.
Click Start, then press Space / arrow keys or tap the on-screen bar to cycle colors. Exit with the Exit button or Esc.
How to use this test
Click Start — the test opens fullscreen over this page (nothing is installed, nothing leaves your browser). A control bar at the bottom of the screen lets you switch colors and exit with one tap — touch screens included; the Esc key and your browser's back button work too. Judge the screen in the lighting the test asks for; judging bleed or uniformity in a bright room defeats the test.
Frequently asked questions
What is a dead pixel?
A pixel whose power supply has failed. It stays black on every color, on every background.
Dead vs stuck pixel?
A stuck pixel is stuck ON (usually red, green, or blue on black). A dead pixel is stuck OFF (black on white). Stuck pixels can sometimes be revived.
Can I test a laptop screen?
Yes — every test on this site runs in your browser at your screen native resolution.