24 / Device Tests
Dead Pixel & Screen Test
Run full-screen color, bleed, banding, uniformity, and sharpness patterns, mark suspected defects, then save a result report.
10 purposeful patterns
Inspect the whole panel
Clean the display, dim the room for the black test, then move through every pattern. Turn on Mark spot when you find something suspicious.
Arrow keys change patterns · M marks a spot · H hides controls · Esc leaves browser fullscreen
Local test record
Result summary
No screen test recorded yet.
Field note
How to check dead pixels, stuck pixels, and bleed
Wipe dust from the screen before testing; a tiny speck can look exactly like a dark pixel. Check white, red, green, and blue to find missing subpixels. A pixel that stays one color may be stuck, while one that stays black across every bright pattern may be dead.
Use black in a dark room for backlight bleed and glow, gray for dirty-screen effect, gradients for banding, and the grid for focus or scaling problems. Keep normal viewing distance as well as a close inspection—camera photos often exaggerate glow.
What this browser test cannot decide
A website cannot read individual hardware pixels or prove a warranty claim automatically. The markers are your visual notes. Compare the result with the seller's pixel policy while the return window is still open.