Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
piCSSel-art - Draw pixel art with CSS!
Pixel Art to CSS - Draw and animate pixel art, export the results to CSS
Pixel Art Studio - A purpose-built drawing tool for pixel artists
JS Kid Pix 1.0.2021 - Kid Pix 1.0 remade in JS/HTML
Pixilart - A drawing app for delightfully retro pixel art