Dominosa Puzzle Generator
A full set of dominoes, from double blank up to the highest double, is laid out flat and the lines between them are rubbed out. Only the numbers remain, and the puzzle is to put the lines back. What makes it a deduction rather than a hunt is that exactly one arrangement fits — which is not true of most grids you could draw, so every grid here is solved exhaustively and thrown away unless the answer is unique.
What this generator does
Tiles the grid with dominoes at random, hands each one a different pair of numbers from the set, and keeps the result only if the numbers alone lead to a single arrangement.
How to use this tool
- Pick which set of dominoes to use — double-six is the usual one.
- Print or copy the grid of numbers.
- Draw boundaries so every domino in the set appears exactly once.
- Show the answer when you are finished, or stuck.
Understanding the controls
- Set of dominoes
- Which set to lay out. Double-six is 28 dominoes on a 7 by 8 grid; the larger sets make longer puzzles rather than merely bigger ones, since there is more to eliminate.
- Seed (optional)
- Type anything to rebuild the same puzzle later, which is how you reprint a page after losing it. Deterministic, not cryptographic.
Common use cases
- A logic puzzle for a puzzle book or a newsletter
- A quiet activity that needs nothing but a pencil
- Teaching systematic elimination without any arithmetic
- A harder challenge with the double-eight or double-nine set
- Practice for anyone who solves these in the paper
How this generator works
The grid is tiled by backtracking, the dominoes shuffled onto it, and the numbers written down. A solver then works only from those numbers: it takes the domino with fewest remaining places, tries each in turn, and counts answers until it finds a second one. A grid with two answers is discarded and another built. The answer shown is the one the solver found, not the arrangement the generator began with — if those could differ, the grid would have had two answers and been rejected.
Randomness and fairness
The tiling and the arrangement of dominoes come from your browser's cryptographic random source unless you give a seed — deterministic, not cryptographic.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- The double-nine set is the largest offered, because the uniqueness search grows faster than the grid does.
- Difficulty is not graded; a unique answer does not promise the deductions are gentle.
- The puzzle is always the full rectangle for the set, which is how Dominosa is normally printed.
- Making a puzzle involves discarding grids, so a fresh puzzle takes a moment on the larger sets.
Privacy and your data
The puzzle is built in your browser. No grids, answers or seeds are transmitted or stored.
Related generators
- Nonogram GeneratorPrintable nonograms whose clues are proved to have exactly one solution, and to be solvable without guessing.
- Hitori Puzzle GeneratorShade out the repeats without letting two shaded cells touch or the rest come apart, with a single answer proved by construction and by search.
- Kakuro GeneratorCross-sum puzzles where every run adds to its clue using distinct digits — every clue satisfiable by construction.
- Suguru Puzzle GeneratorPrints a Suguru — also called Tectonic — where each region holds 1 up to its size and no two equal numbers touch, with exactly one answer.
- Printable Puzzle Book GeneratorBuilds a printable book of up to 250 sudoku, mazes, word searches, nonograms, fill-in crosswords and codewords — sectioned, ramped from gentle to hard, numbered front to back, with an answer key that matches.