How to play Sudoku
- Fill every empty square with a digit from 1 to 9.
- Each row, each column and each of the nine 3×3 boxes contains every digit exactly once.
- The printed digits are fixed. Every puzzle has one solution and never needs a guess.
←↑→↓ move, 1–9 enter, Shift+digit or N for notes, ⌫ erase, Ctrl+Z undo.
Hints explain one step from your current board. Reveal fills in what a hint proved and is counted separately.