Sudoku is the number puzzle that needs no maths: fill a nine-by-nine grid so every row, every column and every three-by-three box contains the digits one to nine exactly once. This sudoku generator gives you a puzzle with some numbers already placed, plus a solver button if you get stuck and a check button to test your progress. It is distinct from minesweeper, which hides mines behind clues; sudoku hides nothing, and the whole puzzle is logic from the numbers you can see. Because it works on the spot, you can fit it into a busy day without changing your routine, and the result is ready in seconds rather than after a setup process. The tool is free to use as often as you like, and it keeps your inputs private by processing everything on your own device instead of sending data anywhere.
Quick Answer: Fill empty squares with digits 1 to 9 so every row, column and box holds each digit once. Use Check or Solve when stuck. It is free, needs no sign-up, and works instantly in your browser on any device.
Free Online Tool
Sudoku Generator
Fill every row, column and box with 1 to 9.
How to Use the Sudoku Generator
- Look at the puzzle grid and the numbers already placed.
- Click an empty square and type a digit from 1 to 9.
- Check that your digit does not repeat in its row, column or box.
- Press Check Progress to see how many squares are correct.
- Press Solve Puzzle to reveal the full solution if you get stuck.
- Repeat the process whenever you need a fresh result, since the tool is free to use as often as you like.
Key Features
- Full nine-by-nine sudoku puzzle with given numbers
- Type digits directly into empty squares
- Check button counts correct entries so far
- Solver button reveals the complete solution
- Free with no account and no download
- Free unlimited use with no account, download or installation required
Best Practices and Tips
- Start with rows, columns or boxes that are nearly full.
- Pencil in candidates mentally for squares with few options.
- Scan for single-candidate squares before guessing.
- Never guess early; one wrong digit breaks the whole grid.
- Use Check Progress when stuck, then rethink the wrong squares.
- If a result looks unexpected, recheck your inputs before assuming the tool is wrong, since a single mistyped value changes most outputs.
- Use the tool regularly for a week before judging it, since habits and routines only show their real value with repetition.
Common Mistakes to Avoid
- Placing a digit that already appears in the same row or box.
- Guessing instead of eliminating candidates.
- Forgetting to check the three-by-three box, not just rows.
- Filling squares in order instead of starting with the easiest.
- Entering rushed or placeholder inputs and treating the output as final without a quick sanity check.
Frequently Asked Questions
What are the rules?
Every row, every column and every three-by-three box must contain the digits 1 to 9 exactly once each.
How is this different from minesweeper?
Minesweeper hides mines and uses number clues about neighbours. Sudoku shows all given digits and asks you to complete the grid by logic.
What does Check Progress do?
It compares your entries with the solution and tells you how many of your filled squares are correct, without revealing answers.
Is there only one puzzle?
This tool serves one classic puzzle with a solver. Replay it to practise, or use the solver to study the solution pattern.
Is this sudoku generator free?
Yes, completely free with no account needed.
Do I need to create an account?
No. Every tool on this page works without an account, a download or a subscription, and your inputs stay in your browser.
Can I use this tool more than once?
Yes, as often as you like. There are no limits, no credits and no waiting between uses.