Full Screen Dead Pixel Test
Free online dead pixel checker — works on any screen, no download required.
Press F11 for best results on desktop
How to Use the Dead Pixel Test
Follow these four steps for a complete, reliable dead pixel check.
- 1
Launch full screen
Press F11 or click Launch Full Screen above. This removes the browser's address bar and toolbars so the color fills your entire display — the only reliable way to test every pixel, including those near the edges.
- 2
Cycle through all seven colors
Switch colors manually with the buttons, or press Auto Cycle to rotate every three seconds. Each color catches a different type of defect. Never rely on just one or two colors — a pixel that blends into the red background will be obvious on blue.
- 3
Scan your screen methodically
Work top to bottom, left to right, taking five to ten seconds per color. A dead pixel is a consistently black dot on every test color. A stuck pixel holds one color regardless of the background — look for any spot that seems "wrong" for the current color.
- 4
Document any defects you find
Photograph the defect against a bright white background and note when it appeared. This documentation is important for warranty claims. Then decide your next step: try the fix tool for stuck pixels, or check your brand's dead pixel policy for replacements.
What to Look For
What a defective pixel looks like depends on the background color. The dot below simulates a dead pixel on each test color — notice how it disappears completely on black. Stuck pixels (which stay one fixed color) are easiest to spot on their opposite color.
- White:Easiest — dead pixels (black dot) are immediately visible.
- Yellow:Dark dead pixels stand out well. Stuck blue/violet pixels visible.
- Gray:Good mid-tone. Both dark and bright stuck pixels show clearly.
- Red:Stuck red pixel hides here; dead pixels (black) still visible.
- Green:Stuck green pixel hides here; dead pixels and others visible.
- Blue:Stuck blue pixel hides here; dead pixels and others visible.
- Black:Dead pixels are invisible. Only stuck pixels (colored dots) show.
Dead Pixel vs Stuck Pixel — Quick Reference
Most people use "dead pixel" to mean any defective pixel, but the distinction matters because stuck pixels can sometimes be fixed while true dead pixels cannot. Full explanation →
| — | Dead Pixel | Stuck Pixel |
|---|---|---|
| Appearance | Always black — never lit | Fixed color — red, green, blue, or white |
| Cause | Transistor failed (off permanently) | Transistor stuck in on state |
| Visible on | Every color except black | Every color except its own matching color |
| Fixable? | Rarely — usually hardware failure | Sometimes — try rapid color cycling |
| Warranty? | Yes — check manufacturer threshold | Yes — same warranty rules apply |
What to Do If You Find One
Found a defective pixel? You have three options, in order of ease.
Try to fix it — stuck pixels only
If your pixel is colored rather than black, it may be stuck — not dead. Stuck pixels sometimes respond to rapid color cycling, which stimulates the sub-pixel transistor back into normal operation. Run our fix tool for 10–20 minutes and check again.
Try the free stuck pixel fix tool →Check your warranty
Most manufacturers follow the ISO 13406-2 standard, which classifies one or two dead pixels as acceptable. But some brands — notably Dell (Premium Panel Guarantee) and LG (OLED zero-defect policy) — will replace even a single defective pixel. Knowing your brand's threshold before you call saves time.
Dead pixel warranty guide — all brands →Return or replace it
If the defect appeared out of the box and you are within your retailer's return window (typically 15–30 days), you can return the screen without invoking the manufacturer warranty at all. Retailers like Best Buy and B&H have their own dead pixel return policies that are sometimes more generous. Document the defect before you return it.
Frequently Asked Questions
How accurate is this online dead pixel test?▾
The test is as accurate as your screen allows. Each solid color isolates a different failure mode. Full-screen mode eliminates border interference. Any visible pixel defect will be caught by cycling through all seven colors.
Do I need to download anything to use this?▾
No. The test runs entirely in your browser — no software, no app, no browser extension required. It works on Chrome, Firefox, Safari, and Edge on any device.
Why should I test on multiple colors?▾
Different defects show up on different backgrounds. A dead pixel (always black) is invisible on a black screen but obvious on white. A stuck red pixel hides on red but appears clearly on blue or green. All seven colors ensure nothing is missed.
How do I go full screen on a phone?▾
Tap the Launch Full Screen button. On most mobile browsers, this scrolls the page to fill the viewport. For the cleanest result, add the site to your home screen and open it in standalone mode — this removes the browser address bar entirely.
How long should I spend on each color?▾
Five to ten seconds per color is sufficient for a typical screen. For large monitors, scan slowly from corner to corner. The full seven-color test takes under two minutes at a careful pace.
Can I test a monitor connected to my laptop?▾
Yes. Open this test on your laptop, drag the browser window to your external monitor, then go full screen. You're testing whichever display the browser is on. Repeat for each screen you want to check.
What if I find a dead pixel on a brand-new screen?▾
Photograph it against a white background and note when it appeared. Then check whether it qualifies for a warranty replacement under your manufacturer's policy. One dead pixel within the return window is almost always grounds for an exchange.
What's the difference between a dead pixel and a bright white spot?▾
A dead pixel is always black — the transistor is off and the pixel never lights up. A bright white spot is a hot pixel — all three sub-pixels (red, green, blue) are stuck fully on. Hot pixels are most visible on dark backgrounds.