Sudoku
Play free Sudoku online with three difficulty levels, pencil notes, undo, and hints. Pick up where you left off in this browser.
Your progress stays in this browser. No account needed.
Preparing your board…
Progress cannot be saved in this browser. Keep this tab open to finish your game.
Game paused
Your board will be here when you’re ready.
Select a square, then choose a number.
Arrow keys move. Type 1–9 to fill a square.
Your results
| Level | Wins | Best without hints |
|---|
Saved only in this browser. Wins include puzzles completed with hints. Unfinished games do not count.
Clear your recorded results? Your current game will stay.
How to play Sudoku
- Fill each row, column, and 3 × 3 box with the numbers 1–9, using each number once.
- Select an empty square, then choose a number. Turn on Notes to jot down possible numbers.
- Use Check to find incorrect entries, or Hint to fill a square. Undo takes back your last edit.
How do the difficulty levels differ?
Easy starts with about 40 filled squares, Medium with 34, and Hard with 28. Every puzzle has exactly one solution. Levels reflect the number of starting clues, rather than a formal rating of solving techniques.
What do checks and hints do?
Matching numbers in the same row, column, or box are marked as conflicts. Check also compares your entries with the solution. A hint looks for a square with one possibility, or a number with only one place in a row, column, or box, and explains the step. Otherwise it reveals a square. Fill notes writes possible numbers into empty squares using your current entries; Undo restores the previous notes. There is no mistake limit.
Can I use a keyboard?
Use arrow keys to move around the grid, 1–9 to enter numbers, and Backspace or Delete to erase. N switches notes on or off. Ctrl+Z or Command+Z undoes an edit. Tab moves between the grid and the controls.
Will my game be saved?
Your current game is saved on this device when browser storage is available. Reopening the page lets you resume it. Clearing site data removes that progress. The timer pauses when you leave the tab; New game replaces your current board.