Sudoku Solver

Use the arrow keys to move to different cells within the sudoku board.

Solved puzzle in 0 seconds ( 0 ms ).

Solve Your Tough Sudoku Puzzles Above

Stuck on a tough sudoku puzzle? Use our Sudoku Solver above to find the solutions to your puzzles. Simply enter in the known numbers in the appropriate squares, click SOLVE IT, and the solver will quickly return your solution. Simple!

Play Sudoku Puzzles at The Word Finder

We've got our own set of Sudoku Puzzles you can play on The Word Finder. Check the page in the Useful Links section. You can choose your difficulty level, time yourself, and much more!

Welcome to our Sudoku Solver! Our tool can help you solve even the most stubborn Sudoku game.

How to Use the Sudoku Solver

  1. Enter the known data into the grid. Using the tool's main interface, enter all of the numbers as they exist on your board. We recommend entering only the game-given numbers, so you can make sure you haven’t made a mistake. However, if you have a half-solved board, you can also enter the numbers you’ve found yourself. But be careful to enter only the numbers you are sure about, or you risk confusing our tool!
  2. Click ‘solve it’ or ‘clear’. Once you’ve entered your numbers and are sure everything is in the correct spot, click ‘solve it’. Our board will automatically populate all of the remaining squares, giving you a solved game. Or, if you’d like to start over, click ‘clear’ to enter a different board.
  3. If you have entered incorrect data, the board will reset. It’s essential to make sure you are entering numbers correctly. If you enter a puzzle board that cannot be solved, the board will go blank, prompting you to start again. Be careful when entering values! This is also why we recommend entering only the board-given (starting) numbers, instead of numbers you yourself have solved. It will help avoid the possibility you’ve entered an incorrect number.
  4. Check out our Sudoku games to find your next puzzle. Once you’ve solved your Sudoku puzzle, you’ll need new material. Check out the Word Finder’s Sudoku puzzles, also shared in the Useful Links section below.

History of Sudoku

It might surprise you to learn that, despite its name, Sudoku is not from Japan. Sudoku, in its earliest form, actually originated in France. In the 1800s, French newspapers created their own number puzzles, which were designed from magic squares. Magic squares are squares that contain nine numbers, three per row. Each row's numbers must add up to fifteen. Early French puzzles removed some numbers from ‘magic squares’ and challenged players to put them back in using math. Later, in 1895, one French newspaper used magic square puzzles as the basis for its own number game, in which each row and column contained every number from one through nine. However, unlike in modern Sudoku, subsquares were not marked.

The first iteration of modern Sudoku was finally published by Dell Magazines in 1979, and dubbed ‘Number Place’. Though it’s unclear who exactly designed the game, it was most likely created by Howard Garns, a retiree and freelance puzzle constructor from Indiana.

Why the name ‘Sudoku’, then? Number Place was introduced to Japan in 1984 and quickly caught on. It was during this expansion that the name Sudoku was introduced, an abbreviation of a phrase meaning ‘the digits are limited to one occurrence.’ From Japan, the game was introduced to Hong Kong, and from there was reintroduced to Britain and the United States — meaning that the name ‘Sudoku’ was adopted worldwide, and the game’s French and American origins were forgotten.

Tips for Playing Sudoku

If you’re at this page, you’re probably struggling to solve a game. While our Sudoku Solver can help you out in the short-run, here are a few tips for how to get better at Sudoku puzzles:

  1. Work one number at a time.

Though it can be tempting to jump around when solving, try to pick one number at a time and stick with it. This can help make sure you’re not missing obvious solves, and can help you flesh out the board to eliminate possibilities for other numbers. Instead of starting in the left lower corner of the board and looking for answers, pick a number and search for every instance of it on the board. For instance, based on how the board is already filled out, where do you know there have to be more ‘1’s? Work in this way through every number, then come back to the beginning. By this time, you’ve likely filled in at least a few squares, and may have narrowed down options for other numbers.

  1. Mark possibilities in the top corner with pencil. (Or, if you’re playing Sudoku digitally, look for the game’s annotation options.)

One of the best ways to speed up a solve is by using annotations. Oftentimes, even if you cannot precisely narrow down what number fits into a specific square, you can narrow it down to two or three options. Marking these options as you go (in small print, usually in the top right corner) has a few benefits.

First, it can help save you time. Instead of coming back several times in a single solution and having to search again for possibilities, you only have to search once. This can be very helpful, especially as you get better at Sudoku and start racing the clock. Another benefit is that, sometimes, these notes can help you to solve other squares. For instance, if I know that the number ‘1’ must be present in one of two boxes in a sub-square, I can know that a ‘1’ won’t go anywhere else in that square.

  1. Start in the boxes, columns, or rows where there are the most given numbers.

Perhaps an obvious tip, but one worth remembering: it is always easiest to start a solve in the areas with the most ‘given’ numbers, or the numbers already on the board. If you see a square with seven of the nine squares filled in, try there first! Same goes for nearly-filled columns and rows. Though you might be tempted to dive right into tackling the difficult sections of the board, filling out easy sections will actually help narrow down options for unsolved areas, and ultimately facilitate a win for you.

Feedback on Our Sudoku Solver

How do you like our Sudoku Solver? Did you find it useful, or are there more features you’d like to see added? Feel free to reach out to us using the contact link in the footer below to tell us how you use the tool and to give us any suggestions for improvements!