16x16 Giant Sudoku (PuzzleMadness)

About 16x16 Giant Sudoku (PuzzleMadness)

The 16x16 Giant Sudoku stretches the classic puzzle to sixteen rows and columns. Since there are only nine digits, the letters A to G stand in for the other seven values, and every row, column and 4x4 box must hold all sixteen symbols once. The methods are the same as in a 9x9 sudoku, but there is far more grid to cover.

The daily page opens today's puzzle on its own, and its title carries the date (on 3 October 2026 it read "Daily Medium 16×16 Giant Sudoku Puzzle for Saturday 3rd October 2026 (Medium)"). There is a separate dated puzzle for each difficulty: Easy, Medium, Hard, Tough and Mixed. Past days stay in the archive, so a missed puzzle can be played later, and there is a print version and an image download of the grid. PuzzleMadness does not publish solutions: the site tells you when you have finished a grid correctly or made a mistake. Each completed puzzle adds to your total on the 16x16 Giant Sudoku monthly and all-time leaderboards, where only your best score on any one puzzle counts.

Treat the letters exactly like numbers. The quickest progress usually comes from squares whose row, column and box already show fifteen of the sixteen symbols. A giant grid takes much longer than a normal sudoku, so the site's Cloud Save is useful.

PuzzleMadness is a British puzzle site with dozens of daily puzzle types in the browser, from many sudoku variants to logic grids such as Nurikabe, Hashi and Slitherlink. It is free to play and carries ads. A free account keeps track of the puzzles you have finished and puts your name on the leaderboards, and the badges next to usernames mark how many puzzles a player has completed.

How to play 16x16 Giant Sudoku (PuzzleMadness)

1. Open the day's 16x16 Giant Sudoku page and pick Easy, Medium, Hard, Tough or Mixed.
2. Enter digits 1 to 9 and letters A to G; pencil marks help track candidates.
3. Make every row, column and 4x4 box hold each of the sixteen symbols once.
4. Fill the whole grid correctly and the score goes on the leaderboards.

Tips

• Work one symbol at a time across the whole grid; it is easier than scanning sixteen candidates per square.
• Squares in crowded rows and boxes often have only one symbol left.
• Save to the cloud and come back if the grid takes longer than one sitting.

Questions