Screen Tests — Dead Pixels, Banding, Bleed and Frame Rate

Screens fail quietly: one pixel stays black, a gradient shows steps instead of a smooth ramp, the corners glow on dark scenes, or a 144 Hz panel quietly runs at 60. These full-screen patterns make each of those visible in a dark room with nothing more than a browser. Run them when a new display arrives, before a return window closes, or when something looks off in games and you cannot tell whether the panel, the cable or the source is responsible.