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A little time for your Sudoku.

My progress
Errors 0
00:00

Keyboard shortcuts

Enter a number
1–9
Move selection
↑ ↓ ← →
Undo
⌘ / Ctrl Z
Erase
Backspace / Delete
Notes
N
Hint
H
Pause / resume
P

You can also drag a number to any blank cell.

Expert difficulty

Settings

Colour theme

System follows your device’s light or dark appearance.

Remaining Candidates

Show how many of each number are left to place. Hide its button when all nine are on the board.

Fast Notes

Add Fast Notes to the Notes menu. Choose it while playing, or hold the pencil, to add the same note to several cells.

Note Conflict Check

Reject notes blocked by a number in the same row, column, or box, and highlight the numbers blocking them.

Expert Sudoku

Expert Sudoku pushes your solving skills to the limit. These puzzles have minimal starting clues and often require advanced techniques like X-Wing, Swordfish, and coloring strategies. If you thrive on logical challenges and enjoy deep analytical thinking, expert Sudoku delivers the ultimate satisfying solve.

About Expert Sudoku

Expert puzzles are among the most difficult Sudoku can offer. With as few as 17-22 given numbers, you will need mastery of advanced techniques to make progress. This includes X-Wing (eliminating candidates based on rectangular patterns), Swordfish (a more complex version of X-Wing), and sometimes forcing chains or coloring strategies.

What advanced techniques do expert puzzles require?

Expert Sudoku frequently requires X-Wing (finding a candidate that appears in exactly two cells in two different rows, forming a rectangle), Swordfish (the three-row version of X-Wing), Y-Wing, and sometimes coloring or forcing chains. Complete pencil marking and systematic candidate elimination are essential.

How many clues does an expert Sudoku have?

Expert Sudoku puzzles typically start with 17-22 given numbers. The mathematical minimum for a unique Sudoku solution is 17 clues, so expert puzzles operate near that lower bound. Fewer clues means more complex solving paths and the need for advanced deduction techniques.

How can I improve at expert Sudoku?

Master one advanced technique at a time. Start with X-Wing, as it is the most common advanced pattern. Practice identifying it in easier puzzles before tackling expert ones. Keep thorough pencil marks, and when stuck, systematically look for each technique you know. Patience is more valuable than speed at this level.