Hard sudoku

Hard puzzles start with just 27 of the 81 numbers in place.

With two thirds of the board empty, quick wins are rare. Expect to pencil in candidates with Notes across whole rows and boxes before the first numbers fall.

You still get three mistakes and three SOS hints, so spend them carefully.

New to the game? Read how to play.

All levels

• Easy sudoku 42 starting numbers
• Medium sudoku 34 starting numbers
• Hard sudoku 27 starting numbers

Sosudoku is published by Mezware.