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Play puzzles from Easy to Evil with daily challenges, tournaments and printable games.

Sharpen your mind with thousands of free Sudoku puzzles. Clean design, mobile friendly and distraction-free.

  • ✓ Pencil notes
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  • ✓ Dark Mode
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  • ✓ Score Points
  • ✓ Awards

1,000+ puzzles played here every day · Privacy respected · Free forever

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Daily Challenges

Daily Sudoku Challenges

Push yourself every day with fresh challenges. Test your skills, climb the leaderboard, and come back tomorrow for a brand new shot at glory.

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Monthly Best Times

This Month’s Best Times

Speed meets precision meets leaderboards. The month’s fastest times are immortalized on the leaderboard. Think you have what it takes?

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Awards

Sudoku Puzzle Awards

Earn recognition for how you play. From mastering different Sudoku levels to hitting milestones, collect awards that showcase your skills.

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Weekly Tournaments

Weekly Tournaments

Who has been putting in the work this week? Weekly tournaments rank the top players who completed the most Daily Challenges.

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Printable Puzzles

Free Printable Sudoku

Grab your favorites and play anytime without screens. Perfect for travel, classrooms, or quiet time. Instant PDF printing.

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Sudoku Solver

Sudoku Solver

Stuck on a puzzle? Instantly solve any Sudoku with ease. Enter the numbers and let the solver do the rest. Great for learning tricky steps.

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Sudoku History

Sudoku History

Discover the origins of Sudoku, from its beginnings to its rise as a global puzzle phenomenon.

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Sudoku Rules

Rules

New to Sudoku or need a refresher? Learn the simple rules that make Sudoku so addictive. Perfect for beginners and seasoned players.

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What is Sudoku?

Sudoku is a logic puzzle with roots in Number Place, a pencil puzzle created in the late twentieth century and popularised in Japan. From there it spread to newspapers around the world and later to the web and mobile apps. The appeal is simple. You use reasoning rather than arithmetic to complete a clean nine by nine grid, one certain step at a time.

People enjoy Sudoku because it is calm yet engaging. You scan for patterns, remove impossible options, and place digits with confidence. Regular play is known to strengthen attention, support working memory, and build problem solving habits that carry into daily life. If you would like the full story of how the game grew, visit our short overview on the Sudoku history page.

How to Play Sudoku

A board begins with given digits called clues. Your goal is to complete the grid so that each row, each column, and each three by three box contains the numbers one through nine exactly once. No calculations are needed. Every placement follows from logic.

  1. Scan rows, columns, and boxes with many clues and list the digits that are missing.
  2. Use elimination. If a digit already appears in a row, column, or box, it cannot also appear in any empty cell within that region.
  3. Place a digit only when it is certain. If several options remain, record them as gentle pencil marks and refine them as you learn more.
  4. Repeat the scan. Each confirmed entry limits choices around it and progress builds step by step.

Easier puzzles often include thirty or more clues and reveal many singles. Tougher levels start with fewer clues and require more advanced reasoning.

Sudoku Tips for Beginners and Experts

Start with singles

Singles are placements that have only one valid option. They open large parts of the grid and build momentum. A quick way to practice this habit is on the Easy Sudoku page.

Use pencil marks

Notes record which digits could fit a cell. Remove candidates as you rule them out. This method is essential on demanding sets such as Hard Sudoku and Expert Sudoku.

Cross hatching and box scanning

Track one digit at a time across a band of three boxes. When the digit already appears in two of those boxes, it must land in the remaining one. The same idea works in vertical stacks and often clears several cells without guessing.

Advanced strategies

When a board resists simple scans, these techniques help:

  • Naked pairs or triples appear when two or three cells in a unit share the same candidates. Remove those candidates from all other cells in that unit.
  • Hidden pairs occur when two digits can only live in the same two cells within a unit. Lock those cells to that pair.
  • Pointing pairs let you clear a digit from an entire row or column when it can only appear within one box of that line.
  • X Wing and Swordfish use repeating patterns across rows and columns to eliminate candidates at scale.
  • XYZ Wing and related patterns resolve tricky three way interactions among candidates.

Avoid common mistakes

  • After every placement, recheck the affected row, column, and box before moving on.
  • Avoid random guesses. If you feel stuck, review pencil marks or switch focus to a new digit.
  • Take a short pause. Fresh eyes often reveal an option you missed.

Why Play Sudoku Online?

Playing online is quick and convenient. Our board works smoothly on phones, tablets, and desktops. Helpful tools such as undo and redo, a timer, streak tracking, error check, and pencil notes make practice enjoyable without clutter. Join the Daily Challenges, chase times on the Monthly best times board, and collect milestones on the Awards page. If you like friendly competition, enter the Weekly tournaments.

Printable Sudoku Puzzles

Paper play is perfect for travel, classrooms, or quiet breaks. Our PDF collections offer multiple levels so you can print exactly what you need. Visit the Printable puzzles page to download a fresh set.

Sudoku Variations

The classic nine by nine grid is only the beginning. Many players enjoy fresh twists that keep logic skills growing:

  • Killer Sudoku adds small cages with target sums which blend arithmetic with deduction.
  • Diagonal Sudoku also requires the two main diagonals to contain one through nine.
  • Samurai Sudoku connects several overlapping grids to form a large puzzle that rewards patience.

These formats encourage flexible thinking and make returning to the classic board even more satisfying.

Choose Your Difficulty

Pick the level that suits your pace today. Easy boards often take only a few minutes and are great for learning, while Expert and Evil boards ask for advanced methods and more time.

Easy Medium Hard Expert Master Extreme Evil

Stuck on a Board?

Enter your current puzzle and let the helper reveal the next logical step. It highlights the technique involved so you learn while you solve. Try the Sudoku solver.

Need a Quick Rules Reminder?

Refresh the essentials at any time on our concise Sudoku rules page. It is easy to print and share with friends who are learning the game.

Frequently Asked Questions

Is Sudoku good for the brain?

Yes. Puzzles like Sudoku encourage sustained attention, pattern recognition, and structured reasoning. Many players find that a short session provides a calm focus that reduces stress and keeps the mind sharp. While Sudoku is not a medical treatment, it is a healthy mental workout that can become a relaxing daily habit.

Can Sudoku improve memory?

Sudoku challenges working memory because you hold candidate digits in mind while scanning across rows and boxes. Over time this gentle exercise can improve the ability to track information, switch focus, and return to earlier deductions without losing your place.

What is the hardest Sudoku level?

The most demanding boards begin with very few clues and require advanced methods such as X Wing, Swordfish, and other pattern based eliminations. On this site the toughest setting is called Evil. Many players build confidence on Hard and Expert before attempting it so that the experience stays enjoyable.

Can I play Sudoku offline?

Absolutely. Download and print PDF sets from our Printable Sudoku puzzles page. Paper play is convenient for trips, classrooms, and screen free breaks, and it pairs well with online practice.

Start Playing Sudoku Now

Choose a level, open a new board, and enjoy a rewarding session of clear logic today.

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Sudoku Guides and Articles

Sudoku4Adults Launches Version 2.7

Sudoku4Adults Version 2.7 introduces powerful new tools including Dark Mode, Auto Pencil, colour cell shading, puzzle SE ratings, and hardest technique insights — designed to help players solve smarter and play with confidence.

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