Play Sudoku Online for Free

Play sudoku online in your browser, with no sign-up and no download. This page starts at the Medium level; use the switch above the board to choose Easy, Hard or Expert instead.

What Is Sudoku?

Sudoku is a number puzzle played on a grid of nine rows and nine columns, split into nine smaller 3×3 boxes. Some squares already hold numbers. Your job is to fill in the empty ones so that every row, every column and every box contains the numbers 1 to 9 exactly once. You never add or multiply anything: sudoku puzzles are pure logic, and each one on this site has exactly one correct solution that you can reach by reasoning alone.

Free Sudoku With No Sign-Up and No Download

This is free sudoku in the simplest sense. You do not create an account, leave an email address or install an app. Open the page on a computer, tablet or phone and the board is ready. You can play sudoku online free for as long as you like, and your current game is saved in your own browser, so you can close the tab and pick up where you left off later on the same device.

A Brand-New Puzzle Every Time You Play

Every time you open the page or press New Game, your browser builds a brand-new grid from scratch and checks that it has exactly one solution and fits the level you chose. There is no stored list of puzzles behind our free online sudoku games, so there is nothing to memorize.

Mathematicians have counted 6,670,903,752,021,072,936,960 different completed Sudoku grids, roughly 6.67 sextillion. So you will practically never meet the same puzzle twice, and you can never run out. Each grid gets its own number, shown above the board. Press Share this puzzle to copy a link, and anyone who opens it will get exactly the same grid.

Sudoku Medium: Where This Page Starts

Sudoku medium is the level this page opens with, because it suits most players. Each free sudoku medium grid begins with 32 of its 81 numbers in place. That is enough to make steady progress by scanning rows and boxes, but every so often you will need to stop and use pencil notes to see which numbers still fit. A typical game takes 10 to 25 minutes.

If you are after online sudoku medium puzzles that are challenging without being frustrating, this is a good level to settle into. You will use it to practice the habits that later make Hard and Expert grids possible.

Easy, Hard and Expert Levels

Use the level switch above the board to change difficulty at any time. Your game at each level is kept separately, so switching does not lose your place.

• Easy Sudoku: 40 starting numbers. Ideal for beginners and for a quick, relaxed game.
• Medium: 32 starting numbers. The page you are on now.
• Hard Sudoku: 27 starting numbers. You will need notes and a few solving techniques.
• Expert Sudoku: 24 starting numbers. For experienced solvers who enjoy a long think.

A New Daily Puzzle

If you like a routine, try the Daily Sudoku. There is one new Medium puzzle every day, the same for every visitor, and the page counts how many days in a row you have solved it.

Notes, Hints, Undo and Printing

Tap a square, then tap a number on the pad below the board (on a large screen the pad sits to the right). Turn on Notes to pencil in small candidate numbers. When you place a number, matching notes in the same row, column and box disappear on their own. Hint fills in the correct number for the selected square, Undo takes back any move, and Show mistakes marks numbers that clash.

If you prefer pen and paper, Print turns the current grid into a free printable sudoku with large squares that fill an A4 or Letter page. Need a sudoku printable for a train ride or a waiting room? Print a few at different levels and take them with you.

Sudoku for Adults of Every Age

We designed this site as sudoku for adults: large numbers, strong contrast, buttons that are easy to tap, and no time pressure, because the timer can be paused or hidden. A puzzle a day is a popular part of an active routine, and sudoku for seniors is a natural choice: it needs no general knowledge and no fast reflexes, only patient, careful thinking.

Learn the Rules and Get Better

New to the game? Our guide on how to play Sudoku explains the rules with a worked example. When you are ready for tougher grids, the page on Sudoku strategies walks you through solving techniques, from hidden singles to the X Wing.