Dead Pixel Test — Free Online Screen Checker

Display solid colors full-screen to find dead or stuck pixels on any device. Click a color or start the full test.

✓ Free ✓ No sign-up ✓ All devices ✓ Runs locally
Click any color for full screen. Space or → to cycle. Esc to exit. On mobile, tap to change colors.

How to Test Your Screen

A full dead pixel test takes under two minutes. For the most accurate result, use the steps below on each device you want to check.

  1. Clean the screen — wipe with a microfiber cloth. Dust and smudges look like dead pixels.
  2. Set brightness to maximum — bright and stuck sub-pixels are easier to spot at full brightness.
  3. Start the full test above — cycle through all 8 colors (black, white, and the six primaries) and inspect each colored frame from close range.
  4. Mark anything suspicious — a defect that persists on multiple colors is a real dead or stuck pixel, not a smudge.

Dead, Stuck, or Hot?

Pixel defects come in three types, and only one of them is usually fixable. Industry standard ISO 9241-307 classifies all three under the same defect tolerance thresholds.

  • Dead pixel — all three sub-pixels (red, green, blue) have failed. Shows as a solid black dot on every background on monitors, laptop screens, and phones alike. Usually permanent.
  • Stuck pixel — one sub-pixel is locked on. Appears as a red, green, or blue dot that stays the same color even when the screen changes. Often fixable with the stuck pixel fixer.
  • Hot pixel — a sub-pixel that permanently glows bright white. Most common on camera sensors, occasionally seen on laptop LCD panels. Not fixable in software.

Unsure which you have? Read the full dead vs stuck guide →

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Screen Test

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Dead Pixel Guide

Learn about dead vs stuck pixels, causes, fixes, and device-specific testing tips.

Frequently Asked Questions

A pixel where all three sub-pixels (red, green, blue) have permanently failed, appearing as a tiny black dot on your screen. Unlike stuck ones, which display a fixed color, these defective pixels emit no light at all.

Stuck ones can often be fixed using rapid color cycling — try our pixel fixer for 20–30 minutes. Truly dead ones are usually permanent. If fixing doesn't work, check your warranty options.

Yes. Open this page on any device with a modern browser, tap a color to go full screen, and tap to cycle through colors. Works on iPhone, Android, iPad, and Kindle. Set brightness to maximum for the best results.

Dead ones appear black (all sub-pixels off). Stuck ones show a fixed color like red, green, or blue (one sub-pixel locked on). Stuck defects are often fixable; dead ones usually aren't. Read our complete guide for details.

The ISO 9241-307 Class II standard — which most consumer displays follow — allows up to 2 bright defects, 2 dark defects, and 5 total defects per million pixels. But manufacturer policies vary widely: Dell replaces UltraSharp monitors on 1 bright pixel, BenQ has a Zero Bright Dot policy, and LG requires 5 or more combined defects. See the full brand-by-brand comparison.

Test within the retailer return window (typically 14–30 days). Run the full 8-color cycle the day you unbox it, then again after a week of use. Dead pixels occasionally appear after the first heating cycles, so early testing catches both factory defects and infant-mortality failures while the monitor is still eligible for a refund.

A single dead pixel does not physically spread to neighbors, but additional unrelated pixels can fail over time on the same display. If a cluster grows in one region it usually indicates a failing row or column driver rather than pixel "infection" — document it quickly and contact the manufacturer before the defect pattern expands.

Yes. The stuck pixel fixer flashes colors at a rate your display is designed to handle — there is no risk of burn-in or panel damage during a normal 10–30 minute run on modern LCDs. Avoid very long sessions (4+ hours) on OLED screens, where static color patterns can cause temporary image retention.