Gearboxly

Free Dead Pixel Test

Full-screen colours to find dead or stuck pixels.

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What is the Dead Pixel Test?

A single bright dot that never goes dark, or a spot that stays black no matter what's on screen, is the kind of flaw you only notice after the return window closes. This dead pixel test floods your screen with solid colours so faults have nowhere to hide — ideal for checking a new monitor, laptop, phone or tablet.

It runs full-screen in your browser, with nothing to install and nothing uploaded.

Last updated: Aug 27, 2026

What does this tool do?

It fills your entire display with one solid colour at a time — black, white, red, green, blue and more — so any pixel that doesn't match the field stands out. You step through the colours by tapping or with the arrow keys, inspecting for pixels that are stuck on, stuck off, or discoloured, as well as backlight bleed and uniformity issues.

Because a healthy screen shows a perfectly even field, anything that breaks the pattern is worth a closer look.

Key features

Full-screen fields

Solid colours edge to edge.

Full colour set

Black, white, RGB and more.

Quick cycling

Tap or arrow-key through colours.

Any device

Monitor, laptop, phone or tablet.

Private

Runs entirely in your browser.

Example

Input
You just unboxed a new monitor.
Processing
Run the full-screen test and step through each colour.
Output
A bright dot on the black field reveals a stuck pixel — caught in time to return it.

Common use cases

  • New-device buyersInspect a screen before the return window closes.
  • Used-gear shoppersCheck a second-hand monitor or phone.
  • IT & repairDiagnose panel faults quickly.
  • Designers & photographersConfirm a clean, uniform display.
  • GamersVet a new gaming monitor.
  • AnyoneRule out a screen defect.

Benefits

  • Makes tiny pixel faults obvious.
  • Works on any screen with a browser.
  • No install — start testing in seconds.
  • Free and private.

Tips

  • Clean the screen first so dust and smudges aren't mistaken for dead pixels.
  • Test in a dark room — faults and backlight bleed are far easier to see.
  • Look closely at the black and white fields especially: dead pixels show on black, stuck ones on white.
  • A stuck pixel (lit in one colour) can sometimes be revived by gently massaging the spot; a truly dead one usually can't.
  • Do this as soon as you get a new device, while you can still return it.

Common mistakes to avoid

Mistaking dust for a dead pixel

Fix: Wipe the screen first — dust moves or wipes away, a pixel fault doesn't.

Testing in a bright room

Fix: Dim the lights; faults and backlight bleed hide under glare.

Only checking one colour

Fix: Step through them all — a pixel dead on black may look fine on white.

Waiting too long

Fix: Test right away so you're still inside the return or warranty window.

How it works

  1. 1

    Start the test

    Fill the screen with a solid colour.

  2. 2

    Cycle colours

    Tap or use arrow keys to change.

  3. 3

    Inspect closely

    Look for spots that don't match.

Frequently asked questions

A dead pixel stays black on every colour; a stuck pixel is always lit in one colour (red, green or blue). Stuck pixels can sometimes be revived; dead ones usually can't.

Go full-screen, clean your screen first, and step through each colour in a dark room. Any pixel that doesn't match the field is a fault — as long as it isn't just dust.

Yes — it's a quick way to inspect a new monitor, laptop or phone for panel defects before the return window closes.

A dead pixel stays black on every colour; a stuck pixel is always lit in one colour. Stuck pixels can sometimes be revived; dead ones usually can't.

Go full-screen, clean the screen, and step through each colour in a dark room. Any pixel that doesn't match the field is a fault — as long as it isn't dust.

Yes — it's a quick way to inspect a new monitor, laptop or phone before the return window closes.

Yes — free, no sign-up, runs in your browser.

Conclusion

Flood your screen with solid colours to expose dead pixels, stuck pixels and backlight issues in seconds. Clean the screen, dim the room, and step through every colour — and do it the day a new device arrives, while you can still act on what you find.

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