Boards with 23 clues · our most demanding level · unique solution
Expert sudoku is MundoSudoku's ceiling: boards starting with only 23 clues out of 81 cells. Here notes aren't optional — they're the map. You'll need hidden candidates, pairs and triples, box interactions and, on the twistiest boards, patterns like X-Wing. Even so, you'll never have to guess: the unique solution is always reachable by logic.
Review our advanced sudoku techniques before diving in, and check how long a sudoku takes to calibrate your times.
Every Sunday the daily sudoku is expert level and every player faces the same board: the best way to measure yourself. If one resists you, step down to hard sudoku or print expert sudokus as PDF to attack them calmly on paper.
It starts with only 23 clues, close to the theoretical minimum of 17 for a unique solution. Every deduction requires crossing several constraints at once, and without disciplined note-taking it's nearly impossible to stay in control.
Yes. Every expert sudoku at MundoSudoku is generated while verifying the unique solution is reachable by deduction. Techniques like hidden candidates, naked pairs and X-Wing are enough.
Half an hour or more is completely normal, even for strong players. Specialists go under 20 minutes. Time isn't the point though — finishing with zero errors is.
You've completed the sudoku.