8-bit means each colour component of a pixel can take 256 distinct values — 256 shades of red, 256 of green, 256 of blue — for a total palette of about 16.7 million colours. This was the standard for digital video for three decades and remains the default for SDR (Standard Dynamic Range) content: every regular YouTube video, every old-school Blu-ray, every webcam feed, every screen recording.
The strength of 8-bit is universality. Every device on Earth — even budget phones, old laptops, low-end TVs — decodes 8-bit video at full speed in hardware. The format is fast, cheap, well-understood and bulletproof. For SDR content shown on consumer screens, 8-bit is usually visually indistinguishable from higher bit depths.
The weakness is banding on smooth gradients. 256 brightness levels per channel sounds like a lot, but on a clear sunset sky or a foggy morning, the human eye can resolve smaller steps than 8-bit can represent, producing visible stair-step bands of slightly different shade. This is mostly invisible on natural high-contrast content, but obvious on anime, animation, dark cinematography and HDR. For HDR delivery — HDR10, HDR10+, Dolby Vision, HLG — 8-bit is simply not enough, and 10-bit is mandatory. In 2026, the practical pattern is: ship 8-bit for SDR on devices that benefit from maximum compatibility, ship 10-bit everywhere else (it's now decoded in hardware on virtually every device made in the last five years and often produces smaller files at the same quality).
