Binairo — The Binary Puzzle
Fill the grid with 0s and 1s. No three in a row, equal counts, and every row and column must be unique. Also known as binary puzzle, takuzu, or tic-tac-logic.
Binairo
6×6 grid. Learn the consecutive rule and counting.
Standard play. Timer runs. Hints available.
What is Binairo (Binary Puzzle / Takuzu)?
Binairo is a logic puzzle played on an even-sized grid where every cell gets a 0 or a 1. Three rules govern the grid: no more than two consecutive identical digits in any direction, each row and column must have equal numbers of 0s and 1s, and no two rows or columns can be identical. Two digits, three rules, and grids that range from a breezy 6×6 to a grueling 14×14.
The puzzle goes by different names depending on where you are. In the Netherlands and Belgium it is called binary puzzle (or binaire puzzel). In France and Japan the name is takuzu. The mobile game 0h h1 popularized it among casual players, and Conceptis Puzzles markets their version as tic-tac-logic. You might also see it called a binary grid puzzle or simply unruly. The rules are identical regardless of the name.
What makes binairo satisfying is how fast deductions chain together. Place one digit, and the consecutive rule forces its neighbors. That triggers a count completion in the same row. Which creates a new consecutive pair in a crossing column. On small grids this cascade can feel effortless. On larger grids, the uniqueness constraint adds a layer of reasoning that catches even experienced puzzle solvers off guard.
Every puzzle on this site has exactly one solution, verified by a constraint solver before publishing. We have 1,500 binairo puzzles across five difficulty levels, from 6×6 grids that take a couple of minutes to 14×14 grids that can occupy an afternoon. Play binairo online free or print them for offline solving. For a daily binary puzzle challenge, check the daily experiment page.
How to play
Tap or click a cell to cycle through empty, 0, and 1. You can also select a cell and use the number pad to place a digit directly. Toggle color mode in the toolbar to see 0s as blue and 1s as amber, which makes spotting patterns on larger grids much easier.
Binairo has three rules: no three consecutive identical digits, equal counts per row and column, and no duplicate rows or columns. If you are new to the puzzle, learn the three rules on the rules page with worked examples.
Notes mode lets you mark which digits are possible in empty cells. The hint system finds the next logically deducible cell and tells you which technique applies. Three hints are available per puzzle in classic and timed modes. If you prefer a purer experience, challenge mode disables hints and undo entirely.
Play modes
Classic
Timer runs up. Up to 3 hints. Undo available. The default way to play.
Timed Trial
Beat the countdown. Time limit scales with difficulty: 3 min for easy, 25 min for einstein.
Challenge
No hints. No undo. Every digit placement is permanent.
Binairo tips and strategies
Technique by technique, beginner to advanced.
Consecutive forcing
The most fundamental technique. If two adjacent cells in a row or column hold the same digit (say, 0-0), the cells on either side must hold 1. Similarly, if cell A and cell C both hold 0 with an empty cell B between them (0-?-0), cell B must be 1 to avoid three consecutive 0s. This technique alone solves most easy puzzles.
Count completion
Each row and column needs exactly N/2 zeros and N/2 ones. If a row in a 6×6 grid already has three 0s, every remaining empty cell in that row must be 1. Track the count display at the edges of the grid — when one digit hits its limit, the rest fill in automatically.
Sandwich forcing
A variation of consecutive forcing. If you see X-?-X (same digit with an empty cell between), the middle cell must be the opposite digit. In a chain like 0-?-?-0, the two middle cells cannot both be 0 (that would make three 0s), so at least one must be 1. Combined with counting, this often resolves both cells.
Uniqueness elimination
On harder puzzles, the uniqueness rule becomes the key unlocking technique. If two rows are identical in all filled positions and only differ in two empty cells, those cells must be filled to make the rows different. Compare nearly-complete rows and columns against each other to find forced digits.
Difficulty levels
| Level | Grid | Key techniques |
|---|---|---|
| Easy | 6×6 | Consecutive forcing, basic counting |
| Medium | 8×8 | Sandwich forcing, count completion |
| Hard | 10×10 | Uniqueness elimination, combined reasoning |
| Expert | 12×12 | Advanced elimination, multi-row deductions |
| Einstein | 14×14 | Logic-only, no guessing required |