Fill the board so that every row, every column and every 3×3 box holds the numbers 1 to 9, each exactly once.
- Pick a cell, then tap a number on the pad or type it on your keyboard.
- The bright numbers at the start can't be changed.
- A wrong number turns red and counts as a mistake. Fewer mistakes, fewer hints and a faster time give a higher score.
- Notes mode writes small pencil marks so you can keep track of what might go in a cell.
- Hint fills in the right number for the cell you picked.
- Undo takes back your last move. Erase clears a cell.
Keyboard
1–9 place a number
Shift + number: note
←↑→↓ move
Backspace erase
N notes on/off
Ctrl+Z undo
H hint
P pause
Difficulties
Every puzzle is made fresh for you and checked to have exactly one answer. Easy starts with 40–45 numbers and can be solved by finding cells with only one choice. Medium (32–39) needs you to look for the only place a number fits. Hard (26–31) needs cleverer tricks like pairs. Expert (22–25) needs the hardest thinking of all.