Dead Pixel Test
Run nine precise full-screen colour fields with arrow-key controls and an adjustable automatic cycle.
- Fewer clicks, keyboard friendly
- Features others lock behind paywalls
Colour preview
Choose a colour or start the full-screen test. Tap or click the field to advance, and look for a dot or small area that differs from it.
Keyboard controls
How to use
- Wipe the display and turn off Night Light, True Tone or other colour filters.
- Choose Start full-screen test; if the browser blocks it, the test still fills the browser window.
- Inspect every field slowly from edge to edge. Tap or click for the next colour, or use Right Arrow or Space; use Left Arrow for the previous one.
- Use A to turn automatic cycling on or off, then press Esc or Exit test when you are finished.
Why nine colour fields help
White makes permanently dark pixels easiest to see, while black makes always-lit red, green, blue or white pixels stand out. Red, green and blue isolate one sub-pixel at a time. Cyan, magenta and yellow light two sub-pixels together, helping reveal a weak channel that can blend into a primary field. Gray is useful for seeing broad brightness non-uniformity, although it does not diagnose a panel defect by itself.
Dead, stuck and bright pixels are not the same
A dead pixel stays dark and is most visible on white. A stuck or bright pixel stays lit in one or more channels and is easiest to notice on black or on a contrasting colour. Dust, a smudge, and a mark on a screen protector can look similar, so clean the surface first and check whether the spot remains in the exact same display location on several fields. This visual test cannot repair a pixel or determine a manufacturer’s warranty decision.
Use the right display conditions
Open the test on the display you want to inspect; for an external monitor, move the browser window onto that monitor before starting full screen. Use the panel’s native resolution where possible and temporarily disable operating-system colour filters. Dim room lighting for the black and gray fields, but do not judge ordinary IPS glow, OLED near-black behaviour or viewing-angle changes as a single bad pixel without comparing at a normal viewing position.
Frequently asked questions
How do I find a dead pixel?
A dead pixel remains dark on every coloured field and is usually easiest to see as a black dot on the white field. Check red, green and blue as well because a failed individual sub-pixel can be less obvious on white.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel does not light and stays dark, while a stuck pixel remains lit in one or more red, green or blue channels. A stuck red pixel can disappear into a red field but should stand out on black, green or blue.
Why does this test use cyan, magenta and yellow as well as RGB?
Cyan combines green and blue, magenta combines red and blue, and yellow combines red and green. These three two-channel fields complement the three RGB primary fields and can make a weak sub-pixel easier to distinguish from its neighbours.
Can a browser test every pixel on my monitor?
A full-screen browser field can visually cover the active display area, but browser and operating-system bars may remain on some mobile browsers. Inspect the visible field, use the browser’s own full-screen option when available, and move the window to each external display before testing it.
Will this fix a stuck pixel?
No. This page is a visual inspection tool that shows nine static colour fields and an automatic cycle. It does not attempt a flashing repair routine, and a browser test cannot guarantee that a pixel fault is repairable.
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Updated 2026-10-19