Are you struck while solving a Sudoku Puzzle?
You can use the above online web based form to solve any sudoku puzzle for free. Just type the half completed or unsolved puzzle and press "Solve completely". Once you submit the screen will display the results online in the same web based form if your puzzle is a valid. The puzzles are solved in the server, hence it does not cause high load to your browser. The browser is only used to display the solution using a nice web interface. You can also read about the algorithm used to solve sudoku puzzles by clicking on the link "How to Solve a Sudoku Puzzle?" on the left. The link contains detailed explanation of the logic involved in solving Sudoku puzzles. Please make sure you typed in the correct numbers before you submit.
Do you need a hint to solve your Sudoku Puzzle?
Our online web Sudoku solver has "Solve one step" option. Once you submit the screen will display your puzzle with one more step solved. It will fill in the next logical position. It will highlight the new number in red. We highly recommend that you use the option "solve one more step". It will help you learn to solve Sudoku puzzles on your own.
Just solve one more step :)
Our online web Sudoku solver allows you to solve exactly one more step. Did you spend hours and hours hunting for the next one step? Do you think solving one step will let you complete the puzzle independently? Select the radio button corresponding to "solve one more step" and hit submit. On submission the solver will solve exactly one step, from which you can proceed solving your sudoku puzzle again. This can also help if you want to solve your puzzle step by step.
Solve Sudoku puzzles completely!
Our online web interface will also let you solve your sudoku puzzles completely for free. We would like our users use "solve one more step only" option. Use the solve completely option only when you want to verify a puzzle you have manually solved. Puzzles are solved in server, hence there is no load on the browser.
Load a random Sudoku puzzle!
This will load a random Sudoku puzzle from our online database to the web interface. The random puzzle will be of the same difficulty level that you have selected before requesting; by default the difficulty level is medium. The imported puzzle will be automatically color coded. The number of filled in cells value will also be updated after the import. We have more than a million Sudoku puzzles in the server, hence every time you import a random Sudoku puzzle, you will get a new puzzle practically.
Use Pencil
If you want to scribble inside cells, check the checkbox adjacent to "Use Pencil". When you are in pencil mode, you wont be able bind a single number to any cells; you will have to uncheck the checkbox adjacent to "Use Pencil", and then enter your number. With pencil option people should be able to solve any sudoku puzzle using our online web interface with the same comform you get with a pencil, paper and pen. The web interface has additional features like time take, color coding, no of filled in cells etc, which are not available when you use paper and pencil. This option is very handy when you are eliminating values from cells; that is while using techniques other than Naked Single and Hidden Single. For detailed explanation on techniques involved in solving Sudoku puzzles, visit our page on how to solve sudoku puzzle. We hope pencil option provides a rich online experience while solving Sudoku puzzles.
More Options
Our online web interface has lot of functionalities and it is very confusing for new users to understand all of them at once. So we have moved rarely used functionalities to "More Options". We hope this makes the online web interface look simple and elegant to use.
Import your sudoku puzzles to the online web interface :)
This feature helps you to easily fill the form with your sudoku puzzle. You can fill in "0" or "*" or "." or "_" at unknown positions. After importing you can color code your sudoku puzzle or solve it single step or solve it completely by clicking on appropriate buttons. This is the most easiest way to fill the form with your sudoku puzzle.
Color code your puzzles online ;)
Check the checkbox adjacent to "Colorcode" option, to color code your Sudoku puzzle. This will assign each number in the puzzle and it's background to a specific color. We hope this will help you visualize the puzzle better and thus solve it easily. Coloring of numbers happen automatically as you type in numbers in the online web interface; if you don't want to color numbers automatically please uncheck the color code check box in the More options section of the online web interface.
Undo color coding:(
Uncheck the checkbox adjacent to "Color code" option, to undo color coding of your Sudoku puzzle. If you don't like color coding of puzzles, you can use this option to undo the colors. You can also use this if you have made changes in the puzzle you color coded before, however color coding it again should also work fine. We hope color coding helps to visualize the puzzle better and hence solve sudoku puzzles easily.
Save your Sudoku puzzle in the web browser:)
This feature lets you to save your sudoku puzzles. When you click on the button "Save your sudoku puzzle", you will be prompted for a name. The puzzle filled in the grid at the moment will be saved in the browser cookies. You can again click on the button "Load your sudoku puzzle", to fill the grid with one of the puzzle that you have already saved. You can save as many sudoku puzzles as you want. However the saved puzzles are visible only in the machine you saved it. If you want to delete your saved puzzles, you will have to delete your cookies. By default, the puzzles will be stored in your machine for 999 days. However, you will have to remember the name of the puzzles, to load them. If you choose the same name for two puzzles, only one of them will be stored. Please choose a unique name for your puzzles, to prevent them from being over written. The default name for the sudoku puzzles are "puzzle1".
Load your Sudoku puzzle from the web browser:)
This feature lets you to load Sudoku puzzles that you have already stored in your browser. When you click on the button "Load your sudoku puzzle", the browser will prompt you to enter the name of the stored sudoku puzzle. Once you enter the name of the puzzle you stored, it will fill in the grid will that sudoku puzzle, and color code the same. If you do not wish to have your puzzle color coded, please click on the button "Undo color code". You can load as many puzzle as you want. You puzzles won't be deleted from memory, unless you remove the cookies from your browser. They will be in memory for 999 days. If you don't remember the name of your puzzle, try "puzzle1". "Puzzle1", is the default name for your puzzles.
Validate your Sudoku puzzle online!
This feature will analyze the puzzle you have filled in make sure that it is valid. A valid puzzle does not contain more than one occurrence of a given number in a row or column or block. When you manually type in your puzzle, the online web interface automatically validate the puzzle. In case of errors, the solver will blink the numbers that occur more than once in a row or column or block. If you import a puzzle, then you will have to manually uncheck and check the checkbox to valid your sudoku puzzle.
No of filled cells :)
Our online web interface displays the count of numbers filled in the solver grid. The web interface updates the count as you type in more numbers. A valid puzzle can have as low as 17 cells filled in. The count of filled in cells is one of the prime measure of difficulty level of a sudoku puzzle. However the pattern of numbers play a more important role in deciding the level of difficulty compare with number of filled in cells. This count of filled cells gets updated as you type in.
Print your Sudoku puzzle online!
This feature will let you print the Sudoku puzzle that is currently filled in the grid. When you click on the button "Print your Sudoku", you will be redirected to a new page, with your puzzle alone. It will automatically prompt you to print; you can either accept to print it or cancel it.
French, German, Finnish, Dutch, Italian, Spanish, Turkish, Portuguese version!
Free online sudoku puzzle solver is available in French, German, Dutch, Italian, Spanish, Turkish, Portuguese and English. To change the language of your choise, use the drop down box in the top of the left column.
Your Sudoku puzzle will be stored in our online database!
We store all sudoku puzzles that people solve using our online web sudoku puzzle solver. These puzzles if found good, might appear in "Today's Sudoku Puzzle" page someday. If you wish to submit more puzzles for our database, you can use the "Upload Your Sudoku Puzzle to our online database" option in the left menu. Thank you for using our free online web Sudoku puzzle solver.
Solve alphabet or symbol based Sudoku puzzles using our online web interface
If you want to solve alphabet based sudoku puzzles, or symbols based sudoku puzzles you will have to manually convert the alphabets and symbols to numbers and submit to the above online web based form. We will soon release a wrapper on top of our current solver which will help you solve alphabet or symbol based sudoku puzzles. However if you have a 16X16 sudoku puzzle with both numbers and alphabets, you cannot use our current solver. Will will release a 16X16 grid sudoku solver soon.
How do you solve a Sudoku puzzle?
To solve a Sudoku puzzle, you should fill in each cell in the above 9X9 grid with exactly one number from 1 to 9, that satisfy the following rules. Each row, column and block should have all the numbers from 1 to 9; hence exactly one of each. Please note that each row, column and 3X3 block has exactly nine cells. There are various algorithms involved in solving sudoku puzzles. Please check our page titled "How to solve a sudoku puzzle?" for complete details. It explains various algorithms like Naked Single, Hidden Single, Block Column/ Row interactions, Block / Block interactions, Naked Subset, Hidden Subset, X-Wing, Swordfish, XY-Wing, XYZ-Wing, Remote pairs, Coloring, XY Chains, Forcing Chains, Nishio, Trial and Error in detail. There is no complicated math involved in solving sudoku puzzles. If you are good in reasoning, you can solve puzzles quite easily. We wish you good luck in solving your sudoku puzzle.
Interesting facts Sudoku puzzles.
Total number of sudoku grids = 6.671 X 10^21 (assuming symmetrical puzzles to be different; assuming all puzzles leading to single solution as one). It is 10^15 times the total human population in earth!
Sudoku puzzles with as little as 17 numbers filled in has a unique solution. Each sudoku puzzle has only one solution. Not all puzzles can be solved by logical reasoning alone.
A given sudoku puzzle can be transformed to 13056 different sudoku puzzles, by rotating, re-labelling and permutating. Rotating any puzzle in multiples of 90 degrees will result in a new puzzle. Rotation is same as reflection. You can also re-label each number in a puzzle to a different one, thus generating a new puzzle.
The difficulty of a puzzle depends on the pattern of filled in numbers and the count of filled in numbers.