Play Sudoku Online Free

How to play Sudoku

1. The grid is nine by nine, split into nine three-by-three boxes. Some cells are GIVEN; you fill the rest.
2. Every row, every column and every box must hold the digits 1 to 9 once each. That is the whole rule.
3. Tap a cell, then a digit on the pad — or type it. Tap the same digit again to rub it out. A wrong digit turns red and counts as a mistake; fix it and carry on.
4. PENCIL mode writes small candidate marks in a cell instead of a digit. When a digit lands correctly, its mark disappears from the rest of that row, column and box.
5. HINT fills in one cell — the one you have selected if it is empty or wrong, otherwise the first it finds. Hints are counted on the score line.
6. Every puzzle has exactly one solution. Easy leaves about 40 givens, Medium 34, Hard 29, Expert 25: the fewer the givens, the deeper the deductions.

Sudoku strategy

The basics that turn knowing the rules into winning games — what to do first, what to keep, what to avoid.

• Start with the digit that already appears most — eight of a kind on the grid means the ninth has one place to go.
• Scan a box, then its three rows and three columns: a digit that sits in two of the three boxes in a band can go in only one row of the third.
• Look for the cell with a single candidate before the digit with a single cell — both are forced, and the cell is quicker to spot.
• Pencil marks are for the hard grids. Write every candidate for a box, then look for a digit that appears once, and for two cells that share the same two candidates: nothing else in that unit can hold either.
• A mistake is cheap and a guess is not. If you are down to guessing on Expert, pencil the two candidates and follow one until it breaks.

Sudoku FAQ

Are the puzzles different every time?

Yes — each one is generated fresh when you start, and checked to have a single solution, so there is always a way through by deduction.

What makes a puzzle easy or expert?

How many digits you are given. Easy starts with about 40 filled in, Medium 34, Hard 29 and Expert 25; the fewer the givens, the harder the deductions.

Do mistakes cost anything?

A wrong digit shows red and adds one to the mistake count on the score line — nothing else. Fix it and carry on. Hints are counted the same way.

Can I use the keyboard?

Yes: arrows move, 1–9 write, Backspace clears, N toggles pencil marks, H asks for a hint.

Do I need an account?

No. Type a name and play — no signup, no download, nothing to install. Making an account is optional and only exists to keep your stats, nickname and preferences across devices.

Is it really free?

Yes, all of it. Every game on Board Game Universe is free to play, with no premium tier holding anything back.

Can I play on my phone?

Yes. It runs in a mobile browser on phones and tablets as well as on a desktop — there is no app to download.

How do I play with my friends?

Start a table and send your friends the link. They open it, type a name, and sit down. Moves and table chat happen in real time.

Can I play against the computer?

Yes. Add a bot to any table and it plays a proper game — useful for filling a seat while you wait for a fourth.