Dead Pixel Test

How to run a dead pixel test on your screen

A dead pixel is a screen cell that no longer lights up — it stays black on every background. A stuck pixel holds one color (usually red, green, or blue) because a single subpixel is frozen. Both are easiest to find by flooding the display with a solid color and inspecting edge to edge. This tool cycles nine full-screen colors plus a rapid-flash fixer mode, so you can separate real defects from dust and sometimes even recover a stuck subpixel before returning the device.

How to run the test

1. Click or tap Start the Test on the screen you want to check. The page enters full-screen mode so toolbars and notches don't block edge pixels.
2. Cycle through each solid color — white, black, red, green, blue, cyan, magenta, yellow, and gray — using Space, the on-screen arrows, or a tap anywhere on the canvas.
3. Inspect the entire panel edge to edge from roughly 30 cm (12 in) away. Note any pixel that stays a different color from the current background.
4. Run Stuck Pixel Fixer mode on any suspicious area. Rapidly flashing colors for 20–60 minutes can sometimes revive a stuck subpixel by exercising the liquid crystal.
5. Press Esc or F to leave full-screen when you're finished. Record the coordinates and color of any defective pixels before contacting warranty support.

When to use a dead pixel test

• New phone & laptop buyers: Inspect a brand-new screen inside the return window. Defects caught early qualify for hassle-free replacement under most retailer and manufacturer policies.
• UI designers & creators: Verify color-critical monitors before calibration. A single stuck pixel corrupts soft-proofing and can waste hours of layout review.
• QA engineers & developers: Run the test on build-room devices and reference hardware before sign-off. Panel defects slip past automated UI snapshots that only read pixel buffers.
• DIY repair & tinkerers: Diagnose second-hand displays, salvaged panels, and laptop screens before spending money on replacements or repair kits.
• Photographers & video editors: Check editing monitors for dead cells in both shadow and highlight regions before long color-grading sessions or print proofing.

What makes this test reliable

• Pure solid colors with no compression, watermarks, or overlays — every pixel on the panel is given exactly one value to render.
• Nine background colors (white, black, red, green, blue, cyan, magenta, yellow, gray) so you can separate dead, stuck, and hot subpixels in a single pass.
• Full-screen mode with keyboard shortcuts (Space, arrows, R/G/B/W/K, Esc) — no toolbars reflowing the viewport to hide edge pixels.
• Stuck Pixel Fixer mode flashes color sequences rapidly — the same exercise technique monitor manufacturers suggest to revive frozen subpixels.
• Runs entirely in your browser. Nothing is uploaded, no install is required, and your color profile stays untouched.

How accurate is an on-screen test?

A solid-color sweep is the same procedure display manufacturers use on the assembly line. Dead pixels show up as tiny dark specks on the white screen; stuck pixels keep a single color across every background. If a suspicious dot vanishes when you change color, it is dust — wipe the panel and retest before calling support.

Dead pixel test FAQ

What is the difference between a dead pixel and a stuck pixel?

A dead pixel stays black on every background because the subpixel has lost power. A stuck pixel shows the same solid color (typically red, green, or blue) because one subpixel is frozen bright. Stuck pixels can sometimes be revived with a fixer routine; dead pixels almost always require a panel replacement.

How many dead pixels are acceptable under warranty?

Most consumer panels follow ISO 9241-307 Class II, which allows up to 2 bright, 2 dark, and 5 partially defective pixels per million. Premium and professional displays often advertise zero bright-pixel tolerance. Always check your specific warranty document before returning a unit.

Can a stuck pixel fix itself?

Sometimes. Rapidly flashing colors for 20–60 minutes (the Stuck Pixel Fixer mode) can unstick a subpixel by exercising the liquid crystal. Gentle pressure with a microfiber cloth is another option but risks scratching the coating. Results are not guaranteed — if a week of fixer sessions doesn't work, the pixel is likely dead.

Does this test work for phones, tablets, and TVs?

Yes — any screen with a modern browser. On a TV, open the page in a browser app or cast from a laptop, enter full-screen mode, then step back about 1.5× the screen diagonal so you can inspect the whole panel evenly without moving.

Why should I test on every solid color?

A single color can hide defects. A dead (black) subpixel looks normal on a black background but shows up as a dark dot on white. Red, green, and blue screens each expose different subpixel failures because every physical pixel is made of three subpixels — one of each color.

Is this test safe for OLED screens?

A few minutes per color is safe. OLED panels age faster with static images, so avoid leaving any single full-screen color on for extended periods. The Stuck Pixel Fixer mode cycles colors automatically specifically to avoid static burn-in while still exercising the subpixels.