Mosaic online

A tile grid is a handy starting point for cross-stitch, bead or brick mosaics and pixel art, where every square has to be a single color. Reading colors square by square off a smooth photo is impossible; off a tile grid it is easy.

Tile size is set by Amount, a 0 to 100 slider starting at 50. It works out to Amount divided by 3, scaled to the photo, so on a 1400 pixel wide image 50 gives 17 pixel tiles and 100 gives 33. The picture is shrunk until each tile is one pixel, which averages its colors, then enlarged without smoothing, so every tile has hard edges.

Dark grout lines about an eighth of a tile wide are drawn along every tile edge, so each square is easy to count but a little smaller than its cell. There is no limit on how many different colors appear, so a photo can still contain hundreds of shades. For a bead or thread pattern with a short color list, run Dithering on the mosaic with Colours set to the number of shades you own and the method set to None.

Pixelate makes the same squares without the grout, for a plain low-resolution look. Halftone uses round dots of changing size instead of flat tiles. Posterize cuts the number of colors without changing the resolution, so detail stays while the shading turns into bands. Mosaic is the right pick when you need to count squares.