Where the terms come from
8-bit consoles like the NES could only show a handful of colors at once, so their art used tiny palettes and chunky pixels. 16-bit consoles like the SNES could show many more colors, so their art looked richer and more detailed. The names stuck as shorthand for those two looks.
The 8-bit look
Few colors (often 4–16), bold shapes, and visible chunky pixels. It reads as retro and nostalgic. To get it, lock a small retro palette like Game Boy (4 colors) or PICO-8 (16 colors) and use a smaller pixel size.
Tip A locked retro palette is what really sells the 8-bit feel — more than the pixel size does.
The 16-bit look
More colors (32–64), smoother shading, and finer detail while still clearly being pixel art. To get it, use the auto palette with a higher color count, turn dithering on for gradients, and use a slightly larger pixel size.
Which should you use?
For icons, avatars, and a strong nostalgic vibe, go 8-bit: small palette, small grid. For detailed characters, scenes, and photo conversions where you want depth, go 16-bit: more colors, dithering on. There is no wrong answer — try both on the same image and compare.