Extreme Sudoku online for the toughest challenge

Play free Extreme Sudoku online for the hardest SudokuPlayers boards, with very few clues and almost no easy openings.

Extreme puzzles are for solvers who do not mind dense notes and long stalls. The work is proving each step when the grid gives very little away.

Choose Extreme Sudoku only when you want a demanding puzzle. It is slow by design, and one clean deduction can change the whole grid.