Sudoku — free browser game
The classic number puzzle — fill every row, column, and 3×3 box with 1–9.
Controls
Click: select cell · 1–9: fill · 0/Backspace: clear · Arrow keys: cursor · H: hint · R: restart · N: new board
How to play
Tips and detailed strategy
Fill the 9×9 board with the digits 1 through 9 so that every row, every column, and every 3×3 block contains each digit exactly once. The bold given numbers are fixed and can't be changed. Click an empty cell or move the cursor with the arrow keys, then press a number key (or use the on-screen number pad) to place a digit; 0 or Backspace clears the selection. Conflicting digits flash red, and cells in the same row, column, or block as the selection are highlighted to help you scan options. Finishing the board correctly auto-wins and records your time as a best score. Strategy: start with cells that only have one possible digit, and look for 'single position' patterns where a digit fits only one cell in a given block, row, or column. The Hint button (H) fills one correct digit but you only get three hints per board; R resets the current board, N deals a new puzzle.