Hardware Testers
Dead Pixel Test
Find bad pixels in seconds. This dead pixel test fills your whole screen with solid red, green, blue, white and black — a dead pixel stays black, a stuck pixel stays one colour. Ideal for checking a new monitor, laptop or phone before the return window closes.
Dead vs. stuck pixels
Both are single dots that don't display correctly, but they're different faults:
- Dead pixel — stays black on every colour because it receives no power. Usually permanent.
- Stuck pixel — stays lit in one colour (red, green or blue) because a sub-pixel is fixed on. Often fixable.
Cycling solid full-screen colours makes either type jump out: on a red screen a dead pixel is a black dot; on a black screen a stuck pixel glows.
How to run the dead pixel test
- Clean first. Remove dust and smudges so they aren't mistaken for defects.
- Go full-screen. Start the test and let one solid colour fill the whole display.
- Step through colours. Click or use ← → to view red, green, blue, white, black and more.
- Scan every area. Check corners and edges too; press Esc when done.
Can you fix a dead or stuck pixel?
A truly dead pixel (always black) generally can't be fixed in software. A stuck pixel sometimes can: rapidly cycling colours on the area, or gently massaging the spot through a soft cloth, can occasionally free it. There's no guarantee, so don't press hard — you risk creating more damage.
Check it within your warranty window
Manufacturers grade pixel defects against the ISO 13406-2 standard, and many warranties only replace a panel past a set number of dead or stuck pixels. Test a new monitor, laptop or phone immediately — within the return period — so you have options if you find a problem.
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Frequently asked questions
What's the difference between a dead and a stuck pixel?
A dead pixel stays black on every colour (it gets no power). A stuck pixel stays lit in one colour — red, green or blue — because a sub-pixel is fixed on. Stuck pixels can sometimes be revived; dead pixels usually can't.
How do I use the test?
Click 'Start full-screen test', then click or press the arrow keys to cycle colours. Inspect the whole screen on each solid colour — any pixel that doesn't match stands out. Press Esc to exit. Clean the screen first so dust isn't mistaken for a pixel.
Can I fix a stuck pixel?
Sometimes. Gentle methods include rapidly cycling colours on that area or carefully massaging the spot with a soft cloth. There's no guarantee, and a truly dead pixel (always black) generally can't be fixed in software.
How many dead pixels are 'normal'?
Manufacturers publish ISO 13406-2 pixel-defect classes; many warranties only replace a panel past a certain count. Testing early — within the return window — gives you the most options.
Does this work on phones and TVs?
Yes — any screen with a browser. On a TV, open the page in a browser app or cast a full-screen tab. The solid-colour method is exactly how technicians check panels.
Why test before my return window ends?
Pixel defects are easiest to act on early. Many retailers and manufacturers only replace a panel above a certain defect count, so finding problems within the return period gives you the most leverage.