Expert Sudoku — the hardest puzzles online

Expert Sudoku is the ultimate challenge. With exactly 17 numbers given — the absolute minimum for a puzzle to have a unique solution — every cell is a battle. This level is designed for players who have mastered all standard techniques and are ready for the hardest puzzles possible.

At this level, you will need the full arsenal: XY-Wing for eliminating candidates through three linked cells. Coloring to trace chains of logic across the entire grid. ALS (Almost Locked Sets) for the most complex eliminations. Some expert puzzles require techniques that even seasoned solvers find challenging.

Expert puzzles earn the maximum points multiplier of 1x — the fastest path to climbing the global rankings. The average solving time is 467 seconds, but some puzzles will push you to your absolute limit.

On OnSudoku, 292,171 expert puzzles have been solved. These are the puzzles that truly separate the best from the rest.

Think you are ready? Start an expert puzzle and prove your mastery. Or if you need to warm up, try the Hard level first.