16×16 Sudoku: Rules and How to Start

16×16 Sudoku uses sixteen symbols, often 1 to 9 and A to G, in 16 rows, 16 columns and 16 boxes of 4×4. The rules, first moves on a real puzzle and tips.

Updated 2026-11-06

The rules

Fill the grid so that every row, every column and every 4×4 box holds each of the 16 symbols exactly once. As in a 9×9 Sudoku, a good puzzle has exactly one answer.

Which symbols?

There is no single standard. Our printable sheets use 1 to 9 and then A to G. You will also see 0 to 9 with A to F, as in hexadecimal numbers, or the numbers 1 to 16 with two digits in some squares. Whichever set a puzzle uses, the symbols are only names: no arithmetic is involved.

The first moves on a real puzzle

This is the first Easy sheet from our printable 16×16 Sudoku, with 102 symbols given. The 5 marked squares are the first moves a beginner would find, in this order:

59GC6DF3174GBEBG2E7134625AE952GCD381B51763D61BA8F3618925EA529G7B9A28F7843DA2B9C18D3FAG2GF66D74CGE259B584D36

16×16 Sudoku, Easy, sheet 1: the first 5 moves are marked.

Row 1, column 6: G. G has only one place left in its box.
Row 4, column 12: E. E has only one place left in its box.
Row 10, column 4: 2. 2 has only one place left in its box.
Row 11, column 1: B. B has only one place left in its box.
Row 9, column 4: 6. 6 has only one place left in its box.

Printable 16×16 Sudoku →

Tips

Work one symbol at a time: pick it, then look at each box for the places it can still go.
Count what is missing: a row with 14 symbols placed has only two left to find.
Keep notes small. With up to 16 candidates, a square fills up fast.
Write clearly on paper: B and 8, or G and 6, are easy to mix up.
If this is your first giant grid, start with our Easy sheets: they need only squares with one symbol left.

Printable 16×16 Sudoku →

Practice

Every Find the Mistake puzzle on this site has exactly one wrong digit, and you can play each board right on its page.

Play the puzzles →