Classic puzzle
Play Sudoku with live validation.
Pick a difficulty, generate a fresh puzzle, and fill the grid. Invalid entries are highlighted automatically the moment you type them.
How it works
- Select a difficulty to start.
- Select a cell, then tap a number above the grid.
- Conflicting entries turn red instantly.
Choose your difficulty
A new random board is generated each time you make a selection.
Pick a difficulty to begin
The board will appear here once you choose a level.
Current game
Not started
Select a difficulty to generate a puzzle.
Givens
0
Empty cells
81
Conflicts
0
Controls
Tips
- Each row, column, and 3x3 box must contain the numbers 1 through 9 exactly once.
- Red cells indicate a conflict with another number already on the board.
- On touch devices, tap a cell and use the number row above the grid.