Dead Pixel Test
Fill the screen with one colour at a time to spot dead or stuck pixels, uneven backlight and banding — before your return window closes.
At a glance
- Full-screen solid colours — black, white, red, green, blue, cyan, magenta, yellow and grey — make faulty pixels stand out.
- Black reveals stuck (lit) pixels and backlight bleed; white reveals dead (black) pixels and dust.
- A gradient checks for colour banding, and single-pixel patterns check sharpness and scaling.
- A stuck pixel fixer flashes rapid colours over a small square or the whole screen — with a clear warning for people sensitive to flashing light.
- Shows your screen’s real resolution, aspect ratio, scaling, refresh rate (60, 120, 144 Hz…), colour depth and HDR support, plus a pixels-per-inch calculator.
- Works on monitors, laptops, TVs, tablets and phones. Nothing is uploaded.
Step by step
How to check a screen for dead pixels
- 1
Clean the screen
Wipe it with a dry microfibre cloth, so dust isn’t mistaken for a pixel.
- 2
Start the test
Press Start full-screen test. The screen turns black.
- 3
Go through the colours
Click or press → for each colour. Look over the whole screen from about 30 cm away.
- 4
Note what you find
A dot that’s always black is dead; a dot stuck on one colour is stuck. Note where it is for a warranty claim.
Features
Everything you need, nothing you don’t
Twelve test screens
Nine solid colours, a gradient, a pixel grid and a sharpness pattern.
Quick to use
Click, tap or press the arrow keys to move between screens; Esc to finish.
Stuck pixel fixer
Rapid colour flashing over a draggable square or the whole screen.
Refresh rate
Measured from how often the browser draws, snapped to the usual rates.
Screen facts
Resolution, aspect ratio, scaling, colour depth, colour gamut and HDR.
Pixels per inch
Enter the screen size to see how sharp it is.
Dead, stuck or hot pixel?
| You see | Name | What it means |
|---|---|---|
| A black dot on white and colours | Dead pixel | The pixel gets no power. It usually can’t be fixed. |
| A red, green or blue dot on black or other colours | Stuck pixel | One of its parts stays on. Sometimes freed by the stuck pixel fixer or gentle pressure. |
| A white dot on black | Hot pixel | All parts stuck on. Treated like a stuck pixel. |
| Light glowing in from edges on black | Backlight bleed | Normal in small amounts on LCD screens; OLED screens don’t have it. |
Before you return a screen
- Check the return window: many shops accept returns for any reason for a short time — test a new screen on day one.
- Read the pixel policy: manufacturers often allow a few faulty pixels before a replacement is due, so count them and note where they are.
- Take a photo of the fault on a solid colour for your claim.
- OLED burn-in shows as faint shapes on the grey screen — common on phones with always-on bars.
FAQ
Frequently asked questions
How do I test for dead pixels?
Can a dead pixel be fixed?
Is the stuck pixel fixer safe?
How accurate is the refresh rate?
Does it work on phones and TVs?
Is anything uploaded?
Keep going
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