Screen Test Tools

A small set of full-screen display tests that run right in your browser — a plain white screen, solid color screens and a dead-pixel test — to check any monitor, laptop, TV or phone for stuck pixels, dust and backlight problems. Free, instant, nothing to install.

White

White Screen

Fill the whole screen with pure white — perfect for spotting dust and dead pixels, tracing paper, using it as a lightbox, or as a soft video-call fill light.

Open White Screen → Color

Color Screen

Switch the display between solid red, green, blue, white, black and more. Handy for color checks, mood lighting and testing individual sub-pixels.

Open Color Screen → Test

Dead Pixel Test

Cycle through solid red, green, blue, white and black so stuck or dead pixels show up as dots that don't match. Auto-advances, or step through by hand.

Open Dead Pixel Test → Monitor

Monitor Test

Run through solid colours, black, white and grayscale steps to check a display for dead pixels, backlight bleed, colour uniformity and banding — all in one pass.

Open Monitor Test →

How a Screen Test Works

Every tool here just paints your entire display a single, uniform color and hides everything else. Against a flat field of color, anything wrong with the panel — a pixel that never lights up, one stuck on a color, trapped dust or uneven backlight — stands out immediately.

1

Go full-screen

Open the white screen or color screen and press the button — the page fills your monitor edge to edge with a solid color and clears the browser chrome.

2

Change color to test

Use the arrow keys or the on-screen swatches to move between white, black, red, green and blue. A dead pixel stays black on every color; a stuck pixel stays one color when the rest change.

3

Look closely

Run the dead pixel test and scan the screen at each color. Wipe suspected spots gently — if they move, it's dust, not a pixel fault. Press Esc to exit at any time.

Frequently Asked Questions

What's the difference between a dead pixel and a stuck pixel?
A stuck pixel is permanently lit in one color (red, green or blue) because a sub-pixel is fixed on — it shows up against a different-colored background and can sometimes be revived. A dead pixel gets no power and stays black on every color, including the white screen; it usually can't be fixed. Cycling through solid colors is the quickest way to tell them apart.
Do these tests upload anything or need an install?
No. Everything runs entirely in your browser using standard web APIs — there's no upload, no account and nothing to download. The tools even keep working offline once the page has loaded.
Can I use the white screen as a light or lightbox?
Yes. A full white screen at high brightness works as a simple lightbox for tracing, checking negatives, or as a soft fill light on a video call. Open the white screen, turn brightness up and go full-screen.
Will this work on a phone or TV?
Yes — any device with a modern browser. On a smart TV or phone, open the color screen and tap to reveal the controls. Full-screen support varies by device, but the solid-color fill always works.