Tap to cycle 1 → 4
Tap to cycle 1 → 4
Mini 4×4 sudoku — fill each row, column, and 2×2 box with 1–4.
A 4×4 board is divided into four 2×2 boxes. Some cells are pre-filled clues; others are blank.
Tap a blank cell to cycle its value: 1 → 2 → 3 → 4 → blank. Clue cells can't be changed.
Finish the board with every row, column, and 2×2 box containing 1, 2, 3, 4 exactly once. A new harder-feeling puzzle starts automatically.
Goal: solve as many puzzles as you can.
On a 4×4 board the whole game is the simple rule that 1, 2, 3 and 4 each appear exactly once in every row, column and 2×2 box. Hunt for the line or box that is already three-quarters full, because its empty cell has only one possible value and gives you a free, certain placement. Each fill you make creates new almost-complete lines, so the board unravels in a chain.
When nothing is three-quarters full, switch to the opposite question: pick a number and ask where in a given box it can possibly go, ruling out columns and rows that already contain it. With only four symbols this cross-checking is quick. Always work from certainties, never guesses — a single wrong digit forces you to unpick everything, so a calm scan for the next forced cell beats stabbing values in hopefully.