Last night, I decided to play free online sudoku puzzles games and I knew I wouldn’t need to have a sudoku solver.

I read first this page before playing sudoku to win:

Can you give me some tips for solving Sudoku puzzles?

Think logically about the puzzles, rather than guessing. This means you should only enter a number once you’re sure about it. To get started, look for a number that appears a lot in the grid, and try to work out where else it should go. Also look for rows, columns or 3×3 boxes which are almost full, and see if you can place any of the numbers that are missing. There’s a Sudoku article at Wikipedia which contains many more solving tips.

Where are the puzzle solutions?

Sorry, we don’t provide solutions to the Sudoku puzzles on the site - that would make it too easy! However, you can click ‘How am I doing?’ for assistance - hopefully this will help you find your way. Alternatively, download Web Sudoku Deluxe which allows puzzle solutions to be retrieved and printed.

How do I use the pencil marking option?

Check the ‘Pencil Marking’ box on the ‘Options’ page, then type more than one number in any blank cell. The numbers automatically shrink to show up to 5 possible numbers entered. This option is only available if JavaScript is enabled in your browser.

How can I pencil in a single number as a possibility?

Make sure ‘Pencil Marking’ is on in the ‘Options’ page. Type in the number followed by a symbol of your choice, such as a question mark (?). The number will appear smaller and in a different color, to differentiate it from numbers you are sure of. Once you are certain, remove the extra symbol.

How many different Sudoku puzzles are there?

According to this page, there are 6,670,903,752,021,072,936,960 different completed 9×9 Sudokus. Of course, there are many different puzzles that can be made from the same completed grid, depending on where the blanks are placed.

How do you classify the levels of difficulty?

The difficulty of a puzzle is related to the depth of thinking required. An easy Sudoku can be solved using more simple logic, whereas an evil puzzle needs deeper analysis. Obviously there is also variation between different puzzles, so even within a level some puzzles may seem harder than others.

How are the statistics calculated?

The statistics for solution times are based on four million puzzles solved during one week on websudoku.com.

The analysis excludes puzzles where the user was corrected by the ‘How am I doing?’ button. This ensures puzzles that were solved by trial and error are not counted (if ‘How am I doing?’ was clicked and there were no mistakes, the puzzle is still included.) The statistics also ignore puzzles that were paused or selected by number, since they might have been printed and solved on paper. Finally, puzzles which took over two hours are excluded, since this could be due to a period of inactivity.

The graph on the statistics page shows the number of puzzles solved within one minute of each point. The “Average” shown is the median rather than the mean, since the time distribution is positively skewed.

Why don’t I receive a ranking for my solution time?

A rank is only shown if you complete a puzzle without being told about mistakes by the ‘How am I doing?’ button. This is because puzzles solved with assistance can’t be compared to those completed without help. If you click ‘How am I doing?’ and there are no mistakes, you will still receive a rank when the puzzle is completed.

Can I play Sudoku in different sizes?

Yes - for 4×4 and 6×6 Sudoku puzzles, check out Jigsawdoku, a colorful Sudoku game which is perfect for kids and beginners. Alternatively, download Web Sudoku Deluxe which provides interactive Sudoku puzzles from 4×4 to 16×16. Or you can create a Sudoku Ebook with all the puzzle sizes as well as interlocking “Samurai” Sudoku.

Who runs Web Sudoku?

Web Sudoku is run by Gideon Greenspan and Rachel Lee. Launched in 2005, it rapidly became the most popular Sudoku website on the Internet, attracting millions of unique visitors every month. You can reach us using the feedback page.

What are the terms of use?

You are welcome to play and print an unlimited number of puzzles for personal use. The puzzles provided by Web Sudoku are copyrighted and may not be reproduced in any form. As an exception, puzzles printed from Web Sudoku may be photocopied without modification for family, friends, or a school classroom. If you’re unsure whether something is permitted, please get in touch.

Automated querying of Web Sudoku by a script or any other means is strictly prohibited.

Web Sudoku is not responsible for the content or services provided on externally linked sites.

What is your privacy policy?

Web Sudoku takes your online privacy seriously. When you visit websudoku.com, the only personal information we know about you is your IP address. If you choose to contact us, we will not share your email address or sell it to third parties. Web Sudoku tracks your preferences and game history using cookies in your browser. You may delete or disable cookies from websudoku.com at any time using your browser’s preferences.

Can I purchase Sudoku puzzles for our publication or website?

Yes, Web Sudoku is a leading supplier of Sudoku puzzles for commercial purposes. Please click for more information about Sudoku puzzle syndication or licensing our interactive Sudoku game.

Le sudoku (prononcé /sudoku/ en français, /s??dok?/ en japonais), est un jeu en forme de grille défini en 1979 et inspiré du carré latin ainsi que du problème des 36 officiers du mathématicien suisse Leonhard Euler.

Le but du jeu est de remplir cette grille avec une série de chiffres (ou de lettres ou de symboles) tous différents, qui ne se trouvent jamais plus d’une fois sur une même ligne, dans une même colonne ou dans une même sous-grille.

La plupart du temps, les symboles sont des chiffres allant de 1 à 9, les sous-grilles étant alors des carrés de 3 x 3.

Quelques symboles sont généralement déjà disposés dans la grille, ce qui facilite un peu la résolution du problème complet.