Sudoku 16
The classic number-place puzzle on a big sixteen by sixteen grid with four by four boxes. A new puzzle every day plus thirty levels, every one with a single solution.
- Logic
- New puzzle every day
- Free, plays in your browser
- Mouse or touch
- Added 30 October 2026
- #sudoku
- #dailypuzzle
- #logic
- #16x16
- #numbers
- #levels
Sudoku 16
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A real run of the game, recorded with captions and no sound.
How to play
- Fill the grid so every row, every column and every four by four box holds each of the sixteen symbols once. The symbols are 1 to 9 and then A to G, where A is 10 and G is 16.
- Tap a square, then tap a symbol under the grid. Starting squares are fixed. Squares that break a rule turn red.
- Selecting a square highlights its row, its column and every square with the same symbol, which makes gaps easier to spot.
- Each puzzle has exactly one solution. Today's daily puzzle is the same for everyone, and the levels start with more clues and get sparser.
Controls: mouse or touch. Made by CalcoTools.
Tips and strategy
- Start with a symbol that already appears many times and work out where it must go in each box.
- Look for a row, column or box that is nearly full: the missing symbols are few and the squares are few.
- A red square only means a rule is broken, not which square is wrong. Check the row, the column and the box of the red square.
- Take it a box at a time. A sixteen by sixteen grid is too big to hold in your head, but one box is easy.
FAQ
- Why are there letters in the grid?
- Sixteen symbols are needed and there are only nine digits, so the symbols after 9 are A to G.
- Is there only one answer?
- Yes. Each puzzle is checked by a search to make sure exactly one grid fits the clues.
- Does the daily puzzle change?
- At midnight UTC. Everyone gets the same puzzle on the same UTC day.
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