Display Color Tester
Cycle full-screen colors, gradients, and grey levels to check your screen for dead pixels, stuck subpixels, color banding, backlight bleed, and burn-in.
Full-screen color slides for finding dead or stuck pixels, gradient slides for banding, and grey slides where burn-in ghosts are easiest to see. Advance with a tap or the arrow keys; the labels hide themselves so nothing covers the test.
About this tool
Finding dead and stuck pixels
A dead pixel stays black on every color, so it is easiest to spot on the white slide. A stuck pixel is lit permanently in one color and stands out on the black slide and on the pure red, green, and blue slides, which also isolate which subpixel is at fault. Look closely — at normal viewing distance a single pixel is easy to miss, and clean the screen first so dust is not mistaken for a defect.
Banding and color precision
The gradient slides should ramp perfectly smoothly from black to full color. Clearly visible vertical bands mean the panel (or its current settings) cannot resolve all 256 steps — common with 6-bit panels, aggressive dithering, or a graphics driver set to limited output range.
The 16-step staircase is the control: its bars are supposed to be sharply separated and individually uniform. If neighboring bars merge, shadow or highlight detail is being crushed.
Burn-in and image retention
Ghost outlines of interface elements — taskbars, channel logos, keyboards — show up best on the grey slides, especially 50% grey. On LCDs, faint retention is often temporary and fades after the screen shows varied content. On OLED panels, genuine burn-in is permanent: pixel-refresh routines and varied content can reduce its visibility, but no web tool can repair it.
Enable auto-cycle to run through all slides hands-free while you inspect the panel.
This tool helps you find display defects; it cannot fix hardware. For warranty claims, check the manufacturer's dead-pixel policy — many require a minimum number of defective pixels.