Sudoku
Generate and solve Sudoku puzzles with notes, hints, undo, and statistics.
Free & unlimitedWorks offline
00:01
Easy35 cells removedClues: ~4646/81 filled35 remaining
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About this tool
- 1
Start a puzzle
Choose a difficulty level to generate a new Sudoku grid, or enter your own puzzle.
- 2
Fill in numbers
Click a cell and type a number 1-9 to place your answer.
- 3
Use notes mode
Toggle notes mode to pencil in candidate numbers for tricky cells.
- 4
Check or solve
Validate your progress to spot errors, or use the solver to see the full solution.
- Start with rows, columns, or boxes that already have the most numbers filled in.
- Use pencil marks to track possible candidates - eliminate them as you place confirmed numbers.
- Look for naked singles (cells with only one possible value) as the easiest wins.
- If you are stuck, try the pointing pairs technique: if a number in a box is limited to one row or column, eliminate it from that row or column outside the box.
- Multiple difficulty levels from easy to expert
- Pencil mark / notes mode for tracking candidates
- Error highlighting to catch mistakes immediately
- Built-in solver that can complete any valid puzzle
- Timer to track your solve speed
- Practice logic skills with daily Sudoku puzzles at increasing difficulty
- Solve a newspaper or book puzzle by entering it and using hints
- Challenge yourself with timed expert-level puzzles
Harder puzzles have fewer starting numbers and require more advanced techniques like X-wing, swordfish, or chains to solve. Easy puzzles can be solved with basic elimination alone.
Yes. All generated puzzles have a unique solution and can be solved using pure logic techniques without any trial and error.