Black Screen is a minimalist web tool that provides a pure, fullscreen black display. With a single click, you can transform your monitor or mobile screen into a dark screen for a variety of needs. BlackScreen.onl is the instant, no-fuss solution. No downloads, no sign-ups, just a perfect black screen. It’s ideal for backlight bleed testing, dead-pixel checks, and OLED/AMOLED black level inspections.