https://websim.com/@Noobbyss/image-ditherer-color-splitter/13

U WANT ME TO SUICIDE

I tried this with an image of Peter Griffin, when I downloaded the pixel colors, I couldn’t find them.

I prefer using Sonkii's image dither https://websim.com/@Sonkii/image-color-splitter-kiwami/23

But if it's pixel art you can export each color without dithering.