Sudoku puzzles
960 puzzles across four levels, each one solved by a technique simulator before it was published. Pick a level, or jump straight into a board.
Easy
Solvable by scanning alone — naked and hidden singles. A calm warm-up.
Medium
You will want pencil marks: locked candidates, pairs and triples.
Hard
Advanced patterns: X-Wings, triples and tighter candidate logic.
Expert
XY-Wings, forced chains and positions that punish impatience.