Hard Sudoku

Few digits appear on the grid, leaving large sections blank from the first move. Hard Sudoku uses the classic 9x9 layout with 81 cells and 3x3 boxes, but this puzzle game is aimed at players who already know standard Sudoku rules. The low number of preset digits raises the pressure on each placement. Daily puzzle fans will recognize the usual structure, yet this version sits near the top end of difficulty and includes alternate hard boards if one layout isn't enough.

How to play?

Select an empty cell and enter a number from 1 to 9, checking the row and the nearby box before placing it. Hints remain available when a dead end appears, and a replay option resets the board for another attempt. Auto-check for errors can be disabled at the top of the screen for a stricter run. Notes may also be removed completely, leaving only direct number placement on the grid. Another hard puzzle can be chosen right away without leaving the game.