はてなブックマーク

This service lets you generate printable sudoku puzzles which you can download (as Acrobat PDF files), print, and then work out with pencil and paper. The generator produces classic symmetrical puzzles of varying difficulty levels. The difficulty level ("Easy", "Medium", "Hard", "Very hard") appears on the printed page along with a difficulty factor ranging between 0.01 and 1.00 (the higher the va