Pick a difficulty, enter numbers with keyboard or touch, and print the current puzzle whenever you want.
An easy Sudoku starts with around 40 given numbers, so most cells can be solved just by looking carefully. You rarely hit a dead end and almost never need to guess. This level is ideal if you are learning Sudoku, want a relaxed round, or are teaching a child the basic rules. A typical easy puzzle takes about three to eight minutes.
The easy level is aimed at beginners and at anyone who wants to switch off for a few minutes. Because many numbers are already in place, you rarely reach a dead end and almost always get there without guessing. This is how you learn the interplay of row, column and 3x3 box that every harder Sudoku builds on.
Two basic techniques are enough on the easy level. A Naked Single is a cell where only one number remains possible. A Hidden Single is a number that fits only one spot within a row, column or box. Once you spot these two patterns reliably, you can solve any easy Sudoku.
When easy puzzles start to feel too quick, move up to Medium. There you get fewer given numbers and begin to work with pencil marks. The step up feels natural once you can solve an easy grid without guessing.
Start with an easy Sudoku. Focus first on rows, columns and 3x3 boxes that already contain many digits, because those usually reveal the next safe move fastest.
Move to another area of the grid and compare row, column and box again. It also helps to use notes for candidates instead of guessing.
Easy puzzles start with more given numbers and shorter logic chains. Harder levels provide fewer clues, so solving them requires more careful deduction and longer sequences of reasoning.