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Hard sudoku

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28,320 hard puzzles · about 28 clues each

Hard sudoku — play free online

Here the easy moves run out. Hard puzzles stall after the opening and ask for a pattern — an X-Wing, a swordfish or a wing — before they open up again.

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  • Pencil marks, undo and 3 hints per puzzle
  • Your game is saved if you leave and come back
Easier: Medium Harder: Expert
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What to expect from hard sudoku

Hard puzzles are rated 2.5 to 3.4 on the Sudoku Explainer scale. Expect to keep full pencil marks and to look for fish patterns (X-Wing, swordfish), unique rectangles and the first wings. Every puzzle has a single solution and can be solved by logic alone.

New to a technique? Each one is explained step by step, with a diagram and practice puzzles, in the free Sudoku Academy.

Techniques you'll need

X-WingExpert · SE 2.5 – 3.2 SwordfishExpert · SE 3.0 – 3.8 XY-WingExpert · SE 3.2 – 4.0 Unique RectangleExpert · SE 3.0 – 4.0

All difficulty levels

Easy sudoku SE up to 1.4 Medium sudoku SE 1.5 – 2.4 Hard sudoku SE 2.5 – 3.4 Expert sudoku SE 3.5 and up Evil sudoku SE beyond the scale
Race a real player Same puzzle, same moment, live progress. Ranked 1v1 in the Expert division, with its own ELO rating. Prefer paper? Six printable hard sudoku puzzles, new every Monday.

Hard sudoku FAQ

What techniques do I need for hard sudoku?

Everything from the easier levels plus advanced patterns: X-Wing and swordfish, unique rectangles and sometimes an XY-Wing. Each one is explained step by step in the free Sudoku Academy.

How long does a hard sudoku take?

Usually 20 to 45 minutes, depending on how quickly you spot the key pattern.

Do hard sudoku puzzles need guessing?

No. Every puzzle here has one solution that can be reached by logic. If you are stuck, a hint reveals one cell — you get three per game.

How are the puzzles rated?

With Sudoku Explainer, which solves each puzzle the way a person would and scores the hardest step it needs. Hard means a score from 2.5 to 3.4.

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