Dead Pixel & Display Tester

How do I test my screen for dead and stuck pixels?

Open AnyTool Dead Pixel & Display Tester and launch a full-screen colour. It fills your entire display with a solid red, green, blue, white, black, cyan, magenta, yellow or gray field so any faulty pixel stands out: a dead pixel stays black on every colour, while a stuck pixel stays locked on one colour. Click, tap or use the arrow keys to cycle the colours (or let it auto-cycle), add gradients to spot banding and a flat black field to check backlight bleed, and run the built-in stuck-pixel exerciser to try to wake a jammed sub-pixel. Everything runs in your browser — nothing is uploaded.

Full-screen solid colours: red, green, blue, white, black, cyan, magenta, yellow + grays
Dead pixel = always black; stuck pixel = stuck on one colour
Gradients show banding; flat black shows backlight bleed / IPS glow
Stuck-pixel exerciser flashes rapid random colours to try to un-stick a sub-pixel
100% in your browser — tests the display you are viewing, uploads nothing

What is

Dead pixel vs stuck pixel

A dead pixel is a screen pixel that never lights up — it stays black on every colour because its transistor receives no power, and it generally cannot be repaired in software. A stuck pixel is a pixel locked on a single colour because one of its red, green or blue sub-pixels is jammed on or off; it can sometimes be revived by rapidly cycling colours over it (a "pixel exerciser") or by gentle massage, though success is not guaranteed.

Calculators

Related terms

Stuck-pixel exerciserBacklight bleedIPS glowPanel uniformityBanding

Frequently Asked Questions

A dead pixel gets no power, so it stays black no matter what the screen shows and is generally permanent — only a warranty claim or panel replacement truly fixes it. A stuck pixel has a sub-pixel jammed on or off, so it appears as a bright red, green, blue or white dot; because it still receives power it can sometimes be un-stuck. Test by filling the screen with white to spot black dead pixels and with solid colours and black to spot glowing stuck pixels.

A dead pixel is always black on every colour and usually cannot be fixed; a stuck pixel stays lit on one colour and can sometimes be revived.

The AnyTool stuck-pixel exerciser flashes dense random colours about thirty times a second over the affected area to exercise the jammed sub-pixel; leaving it running for ten to thirty minutes, or gently massaging the spot through a soft cloth, frees some stuck pixels. Published estimates put software recovery at around a third of cases, with the best odds when the pixel is caught early. A truly dead (always-black) pixel almost never responds to these methods.

Sometimes — rapidly cycling colours over it or gently massaging it works for roughly a third of stuck pixels, but there is no guarantee.

Dim the room, set brightness fairly high and open the solid black field full-screen: even, faint glow at the corners is normal IPS glow, but bright leaking patches at the edges are backlight bleed. Switch to a flat 50% gray field to reveal clouding or mura — uneven blotches — and use the grayscale and per-channel gradients to check for banding, where a smooth ramp shows visible steps. AnyTool draws all of these with pure CSS and canvas, so there are no images to download.

Display a full-screen black field in a dark room and look at the edges and corners for glowing patches; use a 50% gray field to spot clouding.

The Dead Pixel & Display Tester is 100% client-side: it simply paints colours on the very screen you are using, with no server, account or tracking, and works offline after first load. It runs on any device with a modern browser — tap or use the arrow keys to cycle colours on a phone or tablet, or use the keyboard and fullscreen on a laptop, monitor or TV.

Nothing is uploaded — it runs entirely in your browser and works on phones, tablets, laptops, monitors and TVs.

Fill your screen with full-screen solid colours, gradients and uniformity fields to find dead and stuck pixels, check backlight bleed and banding, and run a stuck-pixel exerciser to try to fix jammed sub-pixels — all in your browser.

Features

Ten full-screen solid colours plus grayscale and per-channel gradients
Dead-vs-stuck detection with click / tap / arrow-key cycling and auto-cycle
Flat black and gray fields for backlight bleed, IPS glow and uniformity
Canvas stuck-pixel exerciser — whole-screen or a draggable box
Honest no-guarantee limits — 100% client-side, nothing uploaded

PriceFree

CategoryCalculator

PlatformAll (browser-based)

PrivacyNothing leaves your device — it only paints colours on your own screen

Input: No input — pick a colour or pattern to fill the screen

Output: Full-screen test patterns, Visual dead / stuck pixel inspection

Detailed Explanation

Methodology

How the Dead Pixel & Display Tester Works

AnyTool Dead Pixel & Display Tester paints test patterns directly onto the screen you are viewing, entirely in the browser. A full-viewport overlay fills the display with a chosen pattern: solid colours are drawn with pure CSS, gradients and colour bands with CSS gradients, and the stuck-pixel exerciser with an HTML canvas that redraws a grid of random RGB cells about thirty times a second. The Fullscreen API removes the browser chrome so the pattern reaches every edge, the cursor auto-hides after a moment of stillness, and you cycle the solid set by clicking, tapping or pressing the arrow keys or Space — optionally on an auto-cycle timer. No images are loaded and nothing is sent to a server.

Solid colours via CSS; gradients via CSS gradients; exerciser via canvas
Fullscreen API fills the whole panel; cursor auto-hides when idle
Cycle with click / tap / arrow keys / Space, or a 1–10s auto-cycle
Exerciser redraws random RGB cells ~30 times per second
All rendering is client-side — no assets, no server round-trip

How It Works

Reading the Results: Dead, Stuck, Bleed and Banding

On a solid white field, a dead pixel appears as a persistent black dot because it receives no power; on solid colours and black, a stuck pixel appears as a dot locked on one colour because a sub-pixel is jammed on or off. Cycling through red, green, blue, white, black, cyan, magenta, yellow and gray confirms which kind a defect is and which sub-pixel is affected. A flat black field viewed in a dark room reveals backlight bleed (bright leaking patches at the edges) and IPS glow (a faint corner glow that is normal), while a 50% gray field reveals clouding or mura, and the grayscale and per-channel gradient ramps reveal banding when a smooth ramp shows visible steps.

Dead pixel: black on every colour (no power)
Stuck pixel: locked on one colour (jammed sub-pixel)
Flat black in a dark room exposes backlight bleed vs normal IPS glow
50% gray shows clouding / mura; gradients reveal banding
Cycling all colours identifies the affected sub-pixel

Limitations

The Stuck-Pixel Exerciser and Its Limits

The exerciser rapidly flashes dense random colours over the whole screen, or over a small box you drag and park on top of the bad spot, to repeatedly switch the jammed sub-pixel and try to free it. It can run over the entire panel or be confined to a draggable region, and is best left working for ten to thirty minutes. Software methods such as colour cycling, sometimes combined with very gentle massage through a soft cloth, recover roughly a third of stuck pixels, with the best odds when caught early — but there is no guarantee, and a truly dead (always-black) pixel almost never responds because it has no power to exercise.

Flashes random colours to switch a jammed sub-pixel
Whole-screen or a draggable box parked over the defect
Best run for 10–30 minutes; gentle massage can supplement it
Recovers roughly a third of stuck pixels — no guarantee
Dead (always-black) pixels almost never respond

Privacy & Security

Privacy and Compatibility

The tester only draws colours on the device you are using, so there is no upload, account or tracking, and it works offline after first load. It runs on any modern browser across phones, tablets, laptops, external monitors and TVs — tap or use arrow keys on touch devices, or the keyboard and fullscreen elsewhere. Results depend on your eyes, screen brightness, viewing angle and room lighting, so a small amount of IPS glow or edge bleed on a dark field is normal.

Display testing: in-browser (AnyTool) vs typical online dead-pixel checkers
Capability	AnyTool	Typical online checkers
Processing	Runs in your browser	Runs in your browser
Solid colours	10 (incl. cyan/magenta/yellow + 2 grays)	Often 5 (RGB + black/white)
Cycling	Click / tap / arrow keys + auto-cycle	Usually click only
Gradients / banding	Grayscale + per-channel ramps & bands	Often none
Backlight / uniformity	Flat black + 50% gray fields	Sometimes
Stuck-pixel exerciser	Yes — whole-screen or draggable box	Often a separate tool
Fullscreen + hidden cursor	Yes	Varies
Honest dead-vs-stuck limits	Stated plainly	Often overstated
Cost / signup	Free, no signup	Often ad-heavy

AnyTool paints every pattern locally on your own screen and uploads nothing.

Cite This Page

Title: Dead Pixel & Display Tester (full-screen solid colours, gradients, backlight/uniformity fields and a stuck-pixel exerciser, no server)
Author: AnyTool
Published: January 1, 2026
Modified: February 8, 2026
Section: Calculators
URL: https://www.anytool.tech/dead-pixel-tester

Formatted Citation

AnyTool. "Dead Pixel & Display Tester (full-screen solid colours, gradients, backlight/uniformity fields and a stuck-pixel exerciser, no server)." AnyTool, January 1, 2026. https://www.anytool.tech/dead-pixel-tester

A privacy-first, 100% client-side display tester that paints test patterns onto the very screen you are viewing to find and diagnose panel defects. A fullscreen overlay fills the display with ten solid colours (red, green, blue, white, black, cyan, magenta, yellow and two grays) drawn in pure CSS, plus grayscale and per-channel gradient ramps and colour bands, and flat black and 50% gray uniformity fields — cycled by clicking, tapping or the arrow keys and Space, or hands-free on a 1–10 second auto-cycle, with the cursor auto-hidden when idle. A dead pixel shows as a black dot on every colour because it gets no power and generally cannot be fixed, while a stuck pixel shows as a dot locked on one colour because a sub-pixel is jammed; a built-in canvas stuck-pixel exerciser flashes dense random colours about thirty times a second over the whole screen or a draggable box parked on the defect to try to free it, which works for roughly a third of stuck pixels with no guarantee. Flat black viewed in a dark room exposes backlight bleed versus normal IPS glow, a 50% gray field exposes clouding and mura, and gradient ramps expose banding. The page states the dead-versus-stuck and no-guarantee limits honestly, works on phones, tablets, laptops, monitors and TVs, runs entirely in the browser with no images to download, and uploads nothing.