5 Difficulty Levels & Daily Brain Challenges
From beginner-friendly Easy and Medium puzzles to mind-bending Hard, Expert, and Master grids. Track your win rate, best solve times, and current streaks with comprehensive statistics.
Guaranteed Unique Mathematical Solutions
Every 9x9 puzzle is deterministically generated and verified to ensure exactly one unique solution. Use Pencil Notes mode to pencil in candidate numbers, undo any move, and use smart step-by-step hints.
Sudoku Rules Summary
Fill each cell with numbers from 1 to 9 such that each horizontal row, vertical column, and 3x3 block contains each number exactly once without repetition.