Sudoku online, solo or head to head
Play sudoku online on a clean 9x9 board: fill the empty cells so that every row, every column and each of the nine 3x3 boxes contains the digits 1 to 9 exactly once. No arithmetic is involved, only logic. You can solve a grid on your own or share one with another player and take turns placing digits.
Play nowFree · No download · Runs in your browser
How to play
- Create a free Cleverini account, open Sudoku and choose Single player or Multiplayer.
- Tap an empty cell to select it.
- Tap a digit from 1 to 9 on the keypad below the grid; a correct digit is placed in the cell.
- Leave the pre-filled clue cells as they are, since they cannot be changed.
- Keep an eye on the move timer and keep filling cells until the grid is complete.
What it exercises
A sudoku puzzle is pure logic: every digit you place has to be justified by what is already on the board.
Deduction
You rule out digits that already appear in a cell's row, column and box until only one candidate remains.
Pattern recognition
With practice you start to see where a missing digit must go in a box at a glance, by scanning the rows and columns that cross it.
Concentration
A grid has 81 cells and the constraints overlap, so a long, quiet stretch of focus is part of the appeal.
Tips
- Start with the digit that already appears most often on the board; its remaining places are usually easy to find.
- Scan one 3x3 box at a time and ask which digits it is still missing.
- If a row has only one or two gaps, fill them first. Each cell you complete gives the crossing columns and boxes more information.
- Look for a cell where eight different digits already appear across its row, column and box: the ninth digit is the answer.
- Each move runs on a timer, so pick your next cell while you are still thinking about the current one.
- In multiplayer, cells your opponent fills are shown in their own color, and they count for you as extra clues.
Frequently asked questions
Can I play sudoku online free?
Yes. You get sudoku free of charge here, with no ads. It runs in your browser on a phone, tablet or computer. You need a free account to play, which also keeps your level and progress.
What are the sudoku rules?
Fill a 9x9 grid so that each row, each column and each of the nine 3x3 boxes contains every digit from 1 to 9 once. Some cells start filled in as clues, and a well-made puzzle has exactly one solution.
How do you solve a sudoku for beginners?
Work box by box. For each missing digit, check which cells in the box are blocked by the same digit in a crossing row or column. When only one cell is left, that is where the digit goes.
Is there a multiplayer sudoku I can play with someone else?
Yes. Choose Multiplayer and you share one grid with another player, taking turns to place digits while a score at the top shows who is ahead.
Do I need math for this number puzzle?
No. The digits are just nine different symbols. You never add or multiply them; you only check where each one is still allowed.
Ready for a round?
It opens in your browser. A free Cleverini account keeps your level and lets you play with friends.
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