Binary Puzzle Online (Takuzu)
Fill the grid with 0s and 1s following three simple rules. Also known as Takuzu or Binairo, it is pure logic with no maths at all, and every puzzle here has exactly one solution.
How to play the binary puzzle
Every cell holds a 0 or a 1. You can never have more than two of the same digit next to each other, horizontally or vertically: 0 0 1 is fine, 0 0 0 is not.
Each row and each column contains as many 0s as 1s, and no two rows (or two columns) may be identical. Count as you go: once a row has all its 0s, the rest must be 1s.
Tap a cell to switch between 0, 1 and empty, or use the arrow keys with 0, 1 and Space. Printed digits are fixed. Three in a row turn red right away, Check marks wrong digits and Hint fills in a cell.
Frequently asked questions
Are Takuzu, Binairo and binary puzzle the same game?
Yes. It is the same puzzle under different names: Takuzu in France, Binairo in the Netherlands and much of Europe, and simply binary puzzle in English.
What is the best opening trick?
Look for pairs and gaps. Next to two equal digits (0 0) the neighbours must be the opposite digit, and in a gap like 1 _ 1 the middle must be a 0. Those two patterns solve a surprising share of every grid.
What changes between the levels?
Easy and medium puzzles can be solved with the basic patterns and a little look-ahead. Hard and expert grids are bigger and keep fewer starting digits, so you need to combine the counting and unique-row rules.