Swap Sudoku
Swap Sudoku is a logic puzzle where a completed sudoku is scrambled and you restore it by swapping tiles.
Swudoku is the daily 9×9. A shared board you play by swapping. No timer. Your score is how few swaps you needed.
The name is swap plus sudoku.
If you already play fill-in, Swap Sudoku vs classic sudoku is the comparison.
Open today’s Swudoku if you already want the board.
How you play
The grid starts full. Nothing to type. Tap one tile, tap another, they swap.
You keep going until every row, column, and 3×3 block holds 1–9 once each.
A Double Swap puts both tiles in the correct cell in one move. Those are the cheap scores.
Colours tell you what still has to move. Grey is the wrong cell. Yellow is home, but its row, column, and block are unfinished. Green is home plus any one of those three complete. Dark green is all three.
The tap-by-tap lives in how to play.
The daily 9×9
Everyone gets the same board that day. Most people finish in about 3–5 minutes. That is the ritual.
Score = swaps. Lower is better. Speed does not enter it.
If you’re signed in after a finish, you may see How you compare: a histogram of swap counts for that puzzle.
Play on the web or in the iOS app. Same account syncs game stats both ways for games you played. Archive and past days are web + signed-in. iOS is today’s board only.
Smaller boards
Some versions use a 6×6, or cap how many swaps you get.
Swudoku is the full 9×9. You can take as many swaps as you need. The score just records how many you used.
Questions
What is Swap Sudoku?
A completed sudoku, jumbled, that you put back by swapping tiles. Swudoku is the daily 9×9 form of that.
Is Swudoku Swap Sudoku?
Yes. Same board for everyone that day. No timer. Score is the swap count.
How do you play?
Tap two tiles to swap them. Hunt Double Swaps. Read the colours. How to play has the steps.
Is it free?
Yes. Free on the web and in the iOS app. A free account is optional.
Can I play on my phone?
Yes. Browser on a phone, or the iOS app for today’s board.
Open today’s Swudoku. See how few swaps you need.
More colours, accounts, and Archive notes: FAQs.