Star Battle solver

Stuck on a Star Battle from a newspaper or another app? Draw its regions here and the solver will explain the next logical step, or show the whole solution.

How does the solver work?

It solves the way a person does, one deduction at a time: counting open tiles, comparing the ways a region's stars can fit, spotting regions trapped inside rows or columns, and ruling out tiles that would leave a region with no room. Each step is explained in a sentence. It also checks that the board you drew has exactly one solution, which is the quickest way to find a mistake in the regions.

Which boards does it handle?

Boards from 5×5 to 10×10. Boards of 8×8 and larger are solved with two stars per row, column and region; smaller boards use one, because two stars cannot fit on fewer than eight rows.

To learn the steps it uses, read the technique guides.