Free sudoku, as many as you like
Sudoku is the world’s most popular number puzzle, and you do not need to be good at maths to play it: the digits are just nine different symbols. The whole game is about logic, spotting where each number can and cannot go.
Every sudoku here is freshly generated, so you will never run out of puzzles. Choose easy for a relaxed five minutes, medium or hard for a real workout, or expert when you want a grid that fights back.
A short history of sudoku
The puzzle we call sudoku first appeared in 1979 in an American puzzle magazine under the name Number Place, created by the puzzle designer Howard Garns. In the 1980s the Japanese publisher Nikoli made it popular in Japan and gave it the name sudoku, short for a phrase meaning “the digits must be single”. It became a worldwide craze in 2004 and 2005, when British newspapers started printing it daily.
Sudoku by the numbers
- There are about 6.67 × 10²¹ different completed sudoku grids, a figure calculated by mathematicians in 2005.
- A proper sudoku has exactly one solution. In 2012 researchers proved by computer that at least 17 given digits are needed for that; no 16-clue sudoku with a unique solution exists.
- No arithmetic is ever needed. The digits could be replaced by letters or colors and the puzzle would be the same.
How to play here
Tap a cell, then type a digit on your keyboard. On a phone, use the number pad that appears under the board. To add pencil marks, right-click a cell with a mouse, or on a phone switch on Mark mode (the flag button next to Undo) and tap the cell, then enter the digits. Mistakes that clash with a row, column or box are highlighted.
Choosing a level
- Easy sudoku: solvable by scanning for the one place a digit can go. Perfect for learning.
- Medium sudoku: needs pencil marks and hidden singles.
- Hard sudoku: needs pairs, triples and techniques like the X-Wing.
- Expert sudoku: for experienced solvers who know chains and advanced patterns.
For a twist on the classic, try Killer Sudoku with sum cages, or Jigsaw Sudoku with irregular regions.
How to play Sudoku
- Fill every empty cell with a digit from 1 to 9.
- Each row must contain every digit exactly once.
- Each column must contain every digit exactly once.
- Each of the nine 3×3 boxes must contain every digit exactly once.
Sudoku tips
Scan for the missing digit
Pick one digit, say 7, and look at every box that does not have it yet. Rows and columns that already hold a 7 rule out cells, and often only one cell is left.
Use pencil marks on harder grids
On hard and expert puzzles, note the candidates in each cell. When a cell has only one candidate left, or a digit fits only one cell in a row, write it in.
Look for pairs
If two cells in a row can only be 3 or 8, those two digits belong there. Remove 3 and 8 from every other cell in that row; the same works in columns and boxes.
Frequently asked questions
Is this sudoku really free?
Yes. Every sudoku on MindedGames is free to play in your browser, with no sign-up and no limit on the number of puzzles.
How are the difficulty levels different?
Easy puzzles can be solved by scanning alone. Medium and hard grids need pencil marks and pairs, and expert puzzles call for advanced techniques like X-wings.
Does every sudoku have only one solution?
Yes. Each puzzle is generated and checked so that there is exactly one valid solution.
