Sudoku

How to play

Place digits 1–9 so each row, column, and 3×3 box contains every digit once. Given clues cannot be changed. Empty cells can hold pencil notes while you reason.

Controls

• Click or tap a cell, then choose a number from the pad or keyboard 1–9.
• Toggle Notes (N or Space) to pencil candidates instead of placing values.
• Use Undo / Redo, Erase, Hint, Pause (P), and New Game from the action bar.
• Arrow keys move the selection; Escape clears it.

Smart hints

Hints teach first: they point to a unit, name a technique, explain eliminations, highlight cells, and only then offer to place the answer via Show Me.