Star battle solver

Every step explained

A solver that only fills in the stars doesn't help with the next puzzle. This one explains each cell in a plain sentence and names the technique it used.

Techniques it uses

The solver always tries the simplest technique first, the same order you would use on paper.

Next to a star

Stars never touch, so the eight cells around a star are empty.

Row, column or region is full

Once a row, column or region has its stars, its other cells are empty.

Only place left

When the free cells leave one way to fit the stars, the stars go there.

Region inside one row

A region that fits inside one row takes that row's stars, so the rest of the row is empty. The same works for columns, and for several regions inside as many rows.

Would break a region

A cell is empty if a star there leaves a row, column or region with no room for its stars.

Try and see

On hard puzzles the solver assumes a star, follows the simple techniques, and shows the row, column or region that runs out of room.

Checks your puzzle first

One wrong cell can leave a puzzle with no solution, or with several. The solver checks for both before it starts and tells you which one it found.

Questions

Can it solve a 10×10 two-star puzzle?

Yes. Two-star puzzles need a grid of at least 8×8, and the solver handles 8×8, 9×9 and 10×10. On the hardest ones, many of the steps are try and see.

How do you solve a star battle step by step?

Start with the cells next to stars and the full rows, then look for regions that fit inside one row or column. Step by step mode follows that order on your own puzzle.

Does it work for queens puzzles?

Yes. A queens puzzle is a one-star star battle, so choose 1 star and your grid size. There is a new queens puzzle to play every day.

Is the solver free?

Yes, with no account. It runs in your browser, so the puzzle you draw stays on your device.

Want one to solve yourself? Play today's star battle.