Can I play Sudoku on my phone?

Yes, Sudoku works on any device with a modern browser — phone, tablet, or desktop. The grid is designed for easy touch input on smaller screens.

What difficulty levels are available?

There are 4 difficulty levels: Easy (38+ given digits, great for beginners), Medium (30-37 given digits), Hard (25-29 given digits, requires advanced techniques), and Expert (22-24 given digits, for serious Sudoku solvers).

Yes, a timer tracks how long you take to solve each puzzle. Your best times are saved and submitted to the global leaderboard so you can compete with other players.

Sudoku

The classic number puzzle, refined for the browser. Choose from four difficulty levels, use pencil marks to track candidates, get smart hints when you're stuck, and race the clock to climb the global leaderboard. Your progress auto-saves so you never lose a puzzle in progress.

Puzzle Logic Numbers Classic Free

▶ Play Now — Free

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4 Difficulty Levels

Easy, Medium, Hard, and Expert — from relaxing warm-ups to brain-bending challenges

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Pencil Marks

Note candidate numbers in each cell — an essential technique for harder puzzles

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Smart Hints

Stuck? Get a contextual hint that teaches you the logic without giving away the answer

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Cloud Save

Auto-save in your browser, or sync across all devices with a free GameVolt account

How to Play Sudoku

The goal is simple: fill every cell in the 9x9 grid so that each row, each column, and each 3x3 box contains the digits 1 through 9 exactly once. No repeats allowed. Start with the given numbers and use logic to deduce the rest.

Tap or click a cell to select it, then choose a number. Use pencil mode to jot down candidates when you're not sure. Undo any mistakes with a single tap, and let the auto-save handle the rest so you can pick up right where you left off.

Difficulty Levels

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Easy

38+ given digits. Perfect for beginners or a relaxing session. Most cells can be solved with basic elimination.
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Medium

30-37 given digits. Requires more scanning and occasional pencil marks. A satisfying challenge for regular players.
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Hard

25-29 given digits. You'll need advanced techniques like naked pairs, hidden singles, and pointing pairs.
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Expert

22-24 given digits. For serious solvers. X-Wing, Swordfish, and chain logic may be required. Good luck.

Trophies and Achievements

Sudoku features 31 trophies to unlock. Solve puzzles on each difficulty, beat time targets, complete puzzles without hints, and build solving streaks to earn bronze, silver, gold, and the prestigious platinum trophy. Sign in with a free GameVolt account to sync your trophies across devices.

Leaderboard

Every completed puzzle submits your solve time to the global Sudoku leaderboard, broken down by difficulty. Compare your best times against players worldwide. Can you claim the fastest solve on Expert?

Cloud Save and Cross-Device Play

Your puzzle progress, solve times, and settings save automatically in your browser. Create a free GameVolt account to sync everything across devices — start a puzzle on your phone during lunch and finish it on your laptop at home.

Frequently Asked Questions

Is Sudoku free to play?

Yes, completely free. No ads, no in-app purchases, no downloads. Just open the page and start solving.

Can I play on my phone or tablet?

Absolutely. The Sudoku grid is designed for touch input on any screen size. It works beautifully on phones, tablets, and desktops alike.

What are the difficulty levels?

There are four: Easy (38+ givens), Medium (30-37 givens), Hard (25-29 givens), and Expert (22-24 givens). Each level requires progressively more advanced solving techniques.

What are pencil marks and how do I use them?

Pencil marks let you note possible candidate numbers in a cell before committing. Toggle pencil mode, then tap numbers to add or remove them. It's the classic technique every serious Sudoku player uses.

Is there a timer?

Yes, every puzzle is timed. Your fastest solve times are saved locally and submitted to the global leaderboard when you're signed in. Compete for the fastest time on each difficulty level.