Sudoku

Sudoku is a free online tool that generates a fresh number puzzle in your browser every round — no puzzle database, no network, every grid verified to have exactly one solution. Pick a difficulty, fill the board, and finish it.

Difficulty

0:00Time

0Mistakes

0Hints used

Paused

The timer is frozen. Take a breath — the grid isn't going anywhere.

Puzzle solved

0:00Time

0Mistakes

0Hints

click / tap a cell, then 1–9, ⌫ erase, ←↑↓→ move — pencil notes auto-clear as digits lock in

Every puzzle is generated on this device: a full grid is filled by randomized backtracking, then cells are removed in symmetric pairs only while a solver still finds exactly one solution. Nothing leaves your browser.
Built by Shipwright Studio.