Play Sudoku Online for Free
Play Sudoku online and solve number puzzles directly in your browser. Fill the nine-by-nine grid using logic, keep track of possible numbers, and work toward a correct solution without relying on guesswork. Choose Easy, Medium, Hard, or Expert to find a puzzle that suits your experience.
This free online Sudoku game includes pencil notes, hints, undo, an eraser, a timer, and a mistake counter. Select an empty cell, enter a number from 1 to 9, and use the surrounding rows, columns, and boxes to determine whether your answer fits.
How to Play Sudoku
The objective is to fill every empty cell while following three rules: each row, each column, and each three-by-three box must contain the digits 1 to 9 exactly once.
- Select a difficulty: Choose Easy, Medium, Hard, or Expert before starting a new puzzle.
- Pick an empty cell: Click or tap the square you want to complete.
- Check the grid: Look at the selected cell’s row, column, and three-by-three box to identify which numbers are already present.
- Enter your answer: Use the on-screen keypad or your keyboard to enter a digit from 1 to 9.
- Use Notes when needed: Record possible digits in an empty cell when the correct answer is not immediately clear.
- Correct your work: Use Undo to reverse a recent action or Erase to clear an editable cell.
- Complete the puzzle: Fill every cell with the correct number to finish the game.
Example: If a row contains 1, 2, 3, 4, 5, 6, 7, and 8, its only missing digit is 9. Before entering 9 in the empty cell, check that the same column and three-by-three box do not already contain it.
Understanding Sudoku Rules
Although Sudoku uses numbers, solving it does not require mathematical calculations. The digits act as symbols, and their positions determine which answers are possible.
A digit that is missing from a row is not automatically the right answer for every empty cell in that row. Its position must also agree with the intersecting column and box. Checking all three areas before entering a number helps prevent mistakes.
Sudoku Game Features
Use the built-in controls to manage your puzzle, record possible answers, and recover from an incorrect decision.
Tips for Solving Sudoku
Start with the parts of the grid that already contain the most numbers. These rows, columns, and boxes usually provide more information and can help you find a clear next move.
- Look for missing digits: Check which numbers are absent from a row, column, or box.
- Find single candidates: If only one digit can legally fit in a cell, that is its answer.
- Compare possible positions: A digit may have only one available position within a particular row, column, or box.
- Update your notes: Remove candidates that become impossible after you place a correct number.
- Avoid guessing: If you cannot justify an answer, keep examining the grid or use Notes to record alternatives.
For example, a cell with candidates 2, 5, and 8 cannot contain any other digit. Further examination of the surrounding grid may eliminate two candidates and leave one definite answer. Pencil notes help you keep track of these possibilities without committing to an uncertain entry.
Frequently Asked Questions About Sudoku
Is this Sudoku game free to play?
Yes. You can play Sudoku directly in your browser, select a difficulty, and use the available game controls without needing a printed puzzle.
Which Sudoku difficulty is best for beginners?
Easy is a good starting point because it provides more initial clues. It lets you practise checking rows, columns, and boxes before attempting puzzles that require more candidate analysis.
How many hints do I get?
Each new game starts with five hints. A hint briefly reveals the correct digit for an eligible empty cell and uses one hint from your remaining count.
How many mistakes are allowed?
You can make up to three mistakes in a game. When you enter an incorrect number, it is removed from the cell and your mistake count increases by one. After the third mistake, the game ends, and you can start a new puzzle.
Can I play Sudoku on my phone?
Yes. The game works in a mobile browser. Tap an empty cell and select a number from the on-screen keypad. You can also use the available notes, hint, undo, and erase controls.
Start Your Sudoku Puzzle
Choose a difficulty and begin filling the grid using the numbers already provided. Check each answer against its row, column, and box, and use pencil notes when several candidates remain. If you reach a difficult position, use a hint to get a small amount of help.
Play Sudoku online now and see how efficiently you can complete the puzzle using logic and careful number placement.