Expert Sudoku — very hard puzzles
5
3
8
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9
4
1
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9
1
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2
9
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5
8
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8
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1
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5
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3
Pause
Settings
Keyboard: arrows — select a cell, 1–9 — digit, N — notes, Delete — erase, Ctrl+Z — undo.
Expert sudoku
Expert sudoku is for players who solve hard puzzles with confidence. There are very few givens, and the solution always needs at least one advanced technique: X-Wing, XY-Wing or Swordfish. You can't do without pencil marks here — toggle them with the N key or use "Fill in all notes" in the settings.
Even the hardest puzzles on the site can be solved by logic: we only keep puzzles with a unique solution that doesn't require trial and error. Stuck? Reveal one cell with a hint or read how to solve sudoku with advanced techniques.