SIZE GUIDE · 4×4
4×4 Sudoku complete guide
4×4 uses 2×2 boxes and digits 1–4 only. Rounds finish in 1–3 minutes, making it the perfect starting board for learning Sudoku logic.
Board layout
A 4×4 grid has four 2×2 boxes. Each row, column, and box must contain the digits 1, 2, 3, and 4 exactly once.
Solving patterns
Most 4×4 puzzles can be solved entirely with Naked Singles. When three digits are already in a row or column, the missing cell is forced.
- Scan rows and columns that already have three digits.
- Check each 2×2 box for its missing number.
- Cross-check the row and column to narrow to one candidate.
Playing with kids
With only four digits, pre-school children can give it a try. Start on Easy for quick wins, then move to Normal to introduce noting candidates.
Practice order
- Survey the boardFind the row or column with the fewest blanks.
- Fill forced cellsThree digits visible means one forced answer.
- Cross-check boxesAfter filling rows/columns, verify no box repeats.
- SubmitOnce every cell is filled, the server verifies the grid.
Walk through a 4×4 solve
Step 1 of 4
A near-complete 4×4. Only row 4, column 2 is empty. Let's work out what belongs there using the row, column, and box rules.