Crochet Chart Maker

Crochet Chart Maker (page title: Crochet Tapestry Pattern Maker) turns a JPG, PNG or WebP photo (up to 10 MB) into a single-crochet chart sized by stitch and row gauge. You can use 2 to 10 colors, repaint individual stitches, see color counts, export a PNG with grid and legend, and print.

Processing happens in the browser, and the page says Free, Private, No sign-up. It supports single crochet only, with no C2C or filet.