Dead Pixel Test
Cycle full-screen solid colors to find dead, stuck, and hot pixels on any monitor, laptop, phone, or tablet. Works in your browser — nothing to install.
Space / → next · ← prev · R G B W K jump · F fixer · Esc exit
Screen Ruler
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
- 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.
- 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.
- 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.
- 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.
- 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.