How do I play Sudoku?

Fill the 9x9 grid so that each row, column, and 3x3 box contains the digits 1-9 without repetition. Click a cell to select it, then type a number or use the number pad below the grid.

What are the difficulty levels?

Easy provides 46 starting clues, Medium provides 36 clues, and Hard provides 26 clues. Fewer clues mean a more challenging puzzle that requires more solving techniques.

Are my best times saved?

Yes. Your fastest solve time is saved separately for each difficulty level in your browser's local storage. Beat your own records to see your best time update.

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Sudoku

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How to Play

Objective

Fill the 9x9 grid so that each row, column, and 3x3 box contains all digits from 1 to 9 without repetition.

Basic Controls

Click a cell to select it (bold numbers are given clues and cannot be changed)
Type a number 1-9 on your keyboard or use the number pad below the grid
Press Backspace/Delete to erase a cell
The timer starts automatically and tracks your solving time

Features

Highlighting:Selected cell's row, column, and 3x3 box are highlighted, plus matching values
Error Detection: Conflicting numbers are shown in red
Keyboard support: Arrow keys to navigate, 1-9 to enter, Backspace to erase
Personal Bests: Fastest solve time saved per difficulty

Difficulty Levels

Easy: 46 starting clues - great for beginners and quick games
Medium: 36 starting clues - requires basic Sudoku techniques
Hard: 26 starting clues - demands more solving strategies

Solving Tips

Start by scanning rows, columns, and boxes for obvious placements
Look for “naked singles” (cells with only one possible value)
Eliminate candidates when you place a number in a row/column/box
Take your time - Sudoku rewards logical thinking over speed

About Sudoku

Sudoku is a logic-based number placement puzzle that became a global phenomenon in the 2000s. Despite its association with numbers, Sudoku is purely a logic puzzle - no math is required. The numbers could be replaced with letters or symbols without changing the puzzle.

Each puzzle has a unique solution that can be reached through logical deduction. The modern Sudoku format was popularized in Japan in the 1980s (the name means "single number" in Japanese), though similar puzzles existed earlier in French newspapers.

Our free online Sudoku offers three difficulty levels, each generated fresh on demand. Error highlighting, matching-number highlighting, and a running timer make it easy to work through puzzles and track your best time.

Play Sudoku daily to improve your logical thinking, pattern recognition, and concentration. Track your progress with personal best times for each difficulty level!