Sudoku — free online Puzzle game
Fill every row, column and box with 1 to 9 — three difficulties.
Sudoku is a free online number puzzle. Fill the 9×9 grid so every row, column and 3×3 box holds the digits 1 to 9 exactly once. Pick easy, medium or hard: every puzzle is generated fresh and checked to have exactly one solution, so it can always be solved by logic alone. A timer runs while you play and your best time for each difficulty is saved locally. Play with a mouse, touch or the number keys, in your browser with no download and no sign-up.
Quick start
- Pick easy, medium or hard and press start.
- Tap an empty cell, then tap a number to fill it.
- Fill the whole grid without breaking a rule to stop the clock.
How to play Sudoku
- The board is a 9×9 grid split into nine 3×3 boxes. Some cells start filled in; those clues cannot be changed.
- Fill every empty cell with a digit from 1 to 9.
- Each row, each column and each 3×3 box must contain every digit from 1 to 9 exactly once.
- Look for cells where only one digit can still fit, or for a digit that has only one possible cell left in a row, column or box.
- The puzzle is solved when the grid is full and no digit repeats. Your time is recorded against your best for that difficulty.
Controls
- Select a cell: tap or click it, or move with the arrow keys
- Fill a cell: tap a number on the pad, or press 1–9
- Clear a cell: the erase button, 0, Backspace or Delete
- Start a new puzzle: the new game button or a difficulty button
Solving tips
- Start with the rows, columns and boxes that already have the most clues.
- Scan one digit at a time across the whole board — it is the fastest way to find forced cells.
- Every puzzle has exactly one solution, so you never have to guess.
Frequently asked questions
Does every puzzle have a unique solution?
Yes. Puzzles are generated fresh each time, and clues are only removed while the puzzle still has exactly one solution.
What is the difference between the difficulties?
Harder puzzles start with fewer clues, so you need longer chains of deduction before cells become certain.
Is Sudoku free?
Yes. Sudoku is completely free to play in your browser, with no download, no account and no in-game purchases.
Is my progress saved?
Your best time for each difficulty is saved locally in your browser on this device. Clearing site data resets them.
Can I play on my phone?
Yes. Sudoku is built for touch screens as well as mouse and keyboard, and it fits portrait and landscape screens.