Find every pair
Dominosa
Partition a number grid into a complete domino set.
THE OBJECTIVE
Think it through
Split the grid into dominoes so that every unordered number pair appears exactly once. Each domino covers two adjacent cells.
YOUR CONTROLS
Make your move
Click between two cells to pair them. Right-click between cells to rule out a pairing.
On a phone, use Touch: mark / reverse for a right-click action. Number puzzles include an on-screen number pad.
Choose an easier or harder grid in Type. Use Undo freely. Reveal solution shows the answer; it is a learning aid, not a hint. Use Finish & review to record practice time and actions. Complete 60 seconds of unrevealed practice with at least 3 board actions for the daily streak. Your last puzzle saves in this browser when device storage is available. Use Game → Download save file for a portable backup.
Puzzle engine by Simon Tatham and contributors · MIT licence · Full rules ↗