Dead pixel test

Run a free online dead pixel test with twelve solid fullscreen colors — white, black, RGB primaries, secondaries, orange, and three grey steps. Dark dead pixels show on bright fills; stuck subpixels glow on black. Works on desktop monitors, iPhone, Android phones, OLED TVs, and laptops.

Click to enter fullscreen

Check for dead pixels, bright spots and dark spots

Twelve-color dead pixel test in your browser

TestMyGears fills the screen with pure sRGB solids — no install, no uploads. Cycle white, black, primaries, secondaries, and grey steps in fullscreen so dark dead pixels, stuck subpixels, and hot spots stand out on monitors, phones, and OLED panels.

12-color pure fills

White, black, red, green, blue, cyan, magenta, yellow, orange, and three grey levels cover every sub-pixel fault type. One stuck channel shows on black; a dead pixel vanishes on white.

Fullscreen on any screen

Desktop monitors, iPhone Safari, Android Chrome, Samsung phones, and OLED TVs all support solid fullscreen fills. Arrow keys, F, and auto-cycle keep the pass under three minutes.

Local and private

CSS color fills only — no camera, sensors, or cloud processing. The test runs entirely in your tab and stops when you leave the page.

Dead pixels, stuck subpixels, and hot spots

Not every dot is a dead pixel. Knowing the difference helps you decide whether to wipe the screen, wait for a stuck pixel to recover, or open a warranty claim.

Dead (dark) pixels

A fully dead pixel stays black on white and bright greys. All three sub-pixels failed or the drive transistor is open — the spot never lights up regardless of color.

Stuck subpixels

One color channel stays lit — a red, green, or blue pinprick on black or grey. They are distracting on OLED phones but sometimes recover with gentle pixel exercise.

Hot pixels & dust

A bright white dot on black may be a hot pixel or a stuck channel. Smudges and dust move when you wipe; panel defects stay locked to the same coordinates on every color.

How to run a dead pixel test

A thorough pass takes about three minutes. Maximize brightness, disable night mode, dim the room, and scan the full panel at each color step.

Prepare the panel

Set brightness to maximum and turn off blue-light or night modes that tint the screen. Clean the glass lightly so dust is not mistaken for a stuck pixel. See also: which colors reveal what .

Tip Test within your return window — defects are easier to exchange than repair later
Enter fullscreen and cycle

Click the preview or press F for a full screen dead pixel test. Use ← → to step through all twelve colors, or enable auto-cycle and watch each fill for five to ten seconds. See also: dedicated black screen .

Tip Pause on black for OLED stuck pixels and on white for dark dead pixels
Scan edges and document

Defects cluster near bezels and corners. Note whether the spot appears on one color only or every fill at the same coordinates — that pattern tells support whether it is sub-pixel or full-pixel failure. See also: device-specific zones .

Tip Photograph the artifact with exposure locked for warranty chats

What each test color reveals

White & light grey

Dark dead pixels and missing sub-pixels show as black or grey pinpricks on white and 25% grey. Start here on new LCD monitors before moving to primaries.

Pure black

Stuck and hot subpixels glow on true black — essential for OLED dead pixel tests on iPhone, Samsung AMOLED, and TV panels where emissive pixels should be fully off.

Red, green & blue

Isolates which sub-pixel channel is stuck. A red dot on black that disappears on green points to a red-channel fault rather than full-pixel death.

Secondaries & 75% grey

Cyan, magenta, yellow, and orange stress mixed channels. Mid greys expose subtle uniformity issues that can hide next to pure white or black.

What causes dead pixels

Manufacturing defects

TFT transistors or OLED emissive layers can fail during fabrication. A pixel may be defective from day one even if it only becomes obvious on certain colors.

Physical pressure

Shipping impacts, aggressive cleaning, or pressing on laptop lids can misalign liquid crystals or crack OLED organic layers near the defect site.

Electrostatic discharge

Static shocks in dry environments can destroy drive circuits on monitors and laptops, leaving permanent dark or stuck points.

Panel aging

Years of high-brightness use can wear emissive materials unevenly. True dead pixels rarely heal — stuck pixels sometimes fade with normal use or pixel refresh routines.

Where to test by device

Desktop monitors

Run the test before your retailer return window closes.
Scan corners and the center — IPS glow is normal; fixed dots are not.
One bright pixel on black is often exchange-worthy under strict policies.

iPhone & Android phones

Open in Safari or Chrome, tap fullscreen, and wait for pure black.
OLED and AMOLED stuck pixels are extremely visible on black fills.
Swipe or use arrow keys on a connected keyboard to advance colors.

OLED TVs & laptops

Letterbox black bars should be uniform — bright specks stand out instantly.
Check near logo corners where panel lottery defects sometimes cluster.
Pair with a burn-in pass if you also see retention-shaped shadows.

Samsung & gaming panels

High-refresh gaming monitors benefit from grey-step passes after white/black.
Use custom hex color if a specific game HUD tint makes a fault easier to spot.
Document coordinates if the same dot survives every primary color.

Getting clearer dead pixel results

Maximize brightness

Low brightness hides faint stuck subpixels on black. Crank brightness for the test, then return to comfortable levels for daily use.

Disable color filters

Night Shift, True Tone, f.lux, and gaming color presets tint solids and can mask a dead sub-pixel channel.

Dim the room

Ambient glare on glossy phone and laptop screens makes tiny dots harder to see — especially on near-black OLED fills.

Confirm it is not dust

Wipe the panel and re-check the same coordinates. Defects stay fixed; smudges shift or vanish when the glass is clean.

Dead pixel test FAQs

How do I run a dead pixel test on iPhone?

Open this page in Safari, tap the white preview for fullscreen, then swipe or use volume-remote arrow keys if available. Cycle to black for OLED stuck pixels and white for dark dead pixels. No app install required.

Does this dead pixel test work on Android and Samsung phones?

Yes. Chrome, Samsung Internet, and other Android browsers support fullscreen solid colors. Use arrow keys on a connected keyboard or tap the preview to advance colors on touch-only devices.

What is the best dead pixel test color?

White reveals dark dead pixels; black reveals stuck or hot pixels; pure red, green, and blue isolate sub-pixel faults. Grey steps expose uniformity issues. This tool cycles all twelve automatically.

Can you fix dead pixels with an online test?

An online dead pixel test cannot repair physical panel damage. Stuck pixels occasionally recover with gentle pixel-exercise videos, but true dead pixels require panel replacement or warranty service.

How many dead pixels are acceptable on a monitor?

ISO 13406-2 Class II allows some dark sub-pixels on LCD panels, but any bright pixel on black is hard to ignore. Test within your return window — one visible hot pixel is often exchange-worthy.

Is a white screen dead pixel test enough?

White alone catches dark dead pixels but misses stuck subpixels that only show on black or a single primary. Use a full screen dead pixel test that cycles multiple colors for complete coverage.