Type in the board you have, or paste all 81 characters into any cell. Then ask for one step at a time.
Stuck on a puzzle from a newspaper or a book? Type the digits in and press Next step. Instead of only filling the answer in, it tells you why that digit belongs there. Use Fill it in for the complete solution.
How to use it
- Type your puzzle into the grid. Arrow keys move between cells, and pasting 81 characters into any cell fills the whole grid — use dots or zeros for the blanks.
- Press Next step. You get the technique and its reasoning first, then the digit it places.
- Press it again for the step after that. Fill it in jumps straight to the finished grid.
What it can and cannot do
- It uses the same thirteen techniques as the hints in the game, easiest first. Each has its own page under how to solve.
- If those thirteen cannot find the next step, it says so. Filling it in still works even then.
- A puzzle with more than one answer is refused, as is one with fewer than 17 digits, which cannot have a single answer.
- Digits that break a rule are marked red first, which is how you catch a mistyped board.