Dead Pixel & Screen Test
Fill your screen with solid colours to spot dead pixels, stuck pixels, backlight bleed and colour problems on any monitor, laptop or phone.
The test goes fullscreen. Click or press → to change colour, and Esc to exit.
How to test for dead pixels
- Clean your screen first so dust isn't mistaken for a dead pixel.
- Click Start screen test to go fullscreen.
- Click (or press →) to cycle through red, green, blue, white, black and grey.
- On each colour, look closely for any dot that's the wrong colour. Press Esc to exit.
Dead vs stuck vs backlight bleed
Dead pixel
Stays black on every colour — it gets no power. Usually permanent.
Stuck pixel
Stays fixed on one colour (often red, green or blue). Can sometimes be revived with rapidly changing patterns.
Backlight bleed
On the black screen, look for lighter patches near the edges — that's light leaking through, most visible in a dark room.
Tip: test a new monitor within the first 30 days — most makers accept returns for dead-pixel defects in that window.
Frequently asked questions
How do I test for dead pixels?
Cycle through solid colours fullscreen and look for dots that stay the wrong colour.
Can a dead pixel be fixed?
True dead pixels usually can't. Stuck pixels sometimes recover with flashing patterns or gentle massage.
Does this work on my phone?
Yes — open this page on your phone and run the same fullscreen colour test.