Sudoku
Explore Game Details
Sudoku Rules & Strategies
Sudoku is a logic-based number puzzle. The goal is to fill a 9×9 grid so that each column, row, and 3×3 box contains all digits from 1 to 9.
Basic Rules
- Fill the grid so that every row contains digits 1-9 with no repetition
- Fill the grid so that every column contains digits 1-9 with no repetition
- Fill each 3×3 box with digits 1-9 with no repetition
- Each puzzle has exactly one solution that can be found through logical deduction
How to Play
- Select a difficulty level that matches your skill
- Click on an empty cell to select it
- Use number buttons or keyboard (1-9) to enter a number
- Use the Notes feature to mark possible candidates
- Check your progress with the Check button
- Use hints if you get stuck
Killer Sudoku Rules
- Same basic Sudoku rules apply
- Numbers in each dashed-line cage must sum to the number shown
- No number can repeat within a cage
- Use cage sums to deduce possible combinations
Quick Reference
- Start with rows, columns, or boxes that have the most given numbers
- Use pencil marks to track possible candidates
- Look for 'naked singles' - cells with only one possible number
- Look for 'hidden singles' - numbers that can only go in one place
Solving Strategies
Beginner Strategies
- Scanning: Look for numbers that appear frequently and find where they must go
- Cross-hatching: Check rows and columns to eliminate possibilities in a box
- Counting: Count numbers in a row, column, or box to find missing digits
- Single candidate: When only one number can fit in a cell, fill it in
Advanced Strategies
- Naked pairs: Two cells in a unit with the same two candidates
- Hidden pairs: Two numbers that only appear in the same two cells
- Pointing pairs: When a candidate in a box is restricted to one row/column
- Box/line reduction: Eliminate candidates based on box-line interactions
- X-Wing: Pattern using two rows/columns to eliminate candidates
Pro Tips
- Don't guess! Sudoku is solved through logic, not trial and error
- Use notes/pencil marks to track possibilities
- Take breaks if you're stuck - fresh eyes often spot solutions
- Practice regularly to recognize patterns faster
- Start with easier puzzles and gradually increase difficulty
Frequently Asked Questions
Have another question? Let us know.
What is the goal of Sudoku?
The goal of Sudoku is to fill a 9x9 grid with numbers so that each row, each column, and each 3x3 subgrid contains all digits from 1 to 9 without repetition. This game helps improve logical thinking skills and concentration.
How should I start playing Sudoku?
Choose a difficulty level that suits you (easy, medium, hard, very hard, and insane) and examine the given numbers. Start by identifying the numbers that are already filled in and use the process of elimination to determine the numbers for empty spaces. For example, if a number appears in a row or column, it cannot appear again in that row or column. By gradually narrowing down the options, you'll eventually find the correct number for each space. Remember to stay patient; Sudoku requires logical reasoning, so maintaining focus is essential. Playing Sudoku is enjoyable and also trains your brain, enhancing concentration and problem-solving skills.
How can I improve my Sudoku skills?
Regular Sudoku practice can significantly boost logical thinking skills and patience, with positive effects on mental health. To improve, try solving puzzles of varying difficulties to build sensitivity to number patterns. Additionally, learn and apply specific solving strategies, such as 'naked singles' (if only one number fits in a position, place it directly) and 'hidden pairs' (where two specific numbers can only fit in two specific positions in a row or column, allowing you to eliminate other numbers). Also, pay attention to your mental state. Sudoku challenges may cause frustration or anxiety, so it's important to stay calm and relaxed. Take breaks and shift focus when needed, which can help you return to the puzzle with renewed concentration.
Is this a good choice when I want to take a break from scrolling?
A game that ends is different from an endless feed: one round has a clear finish, so it is easier to stop when the round ends. Play one round as a deliberate break — then close the tab and step away.
Recommended Games
Mini Sudoku
Play smaller Sudoku: easy 4x4 or 6x6 boards with the same logic. Perfect for kids and beginners learning to solve — free, in your browser.
Diagonal Sudoku
Classic Sudoku plus one extra rule: both main diagonals must contain 1-9 too. A tighter, more elegant logic challenge — free, in your browser.
Kakuro
Classic Kakuro crossword puzzle. Fill digits so each horizontal and vertical run sums to its clue without repeats. A perfect logic challenge!
