What is Binairo?
Binairo (also called Takuzu or Binary Puzzle) is a logic puzzle played on a rectangular grid. The objective is to fill every cell with either a 0 or a 1 while satisfying several constraints. Each row and column must contain an equal number of 0s and 1s. No row or column can have more than two consecutive identical digits—for example, three 0s in a row (000) is not allowed. Additionally, every row must be unique, and every column must be unique. These simple rules create surprisingly deep logic puzzles. Every puzzle has exactly one solution. PencilGrid's generator guarantees unique solutions and avoids guessing. All puzzles are solvable using pure logic. Difficulty increases with grid size and the number of given cells. Our daily puzzles rotate through 10×10 grids at varying difficulties. Practice mode offers grids from 6×6 (great for beginners) up to 14×14 (challenging for veterans), each with Easy, Medium, and Hard variants.
Features
Daily Puzzles
New Binairo every day at midnight UTC. Build a streak by solving consecutive days.
Multiple Grid Sizes
Practice on 6×6, 8×8, 10×10, 12×12, and 14×14 grids. Start small and work your way up.
Practice Mode
Unlimited puzzles at Easy, Medium, and Hard difficulty. Perfect for mastering binary logic.
Error Checking
Check your work at any time. Rule violations are highlighted so you can find mistakes.
Undo/Redo
Full undo/redo stack. Experiment freely without fear of losing progress.
Auto-Save
Your progress is saved automatically. Resume any puzzle right where you left off.
Frequently Asked Questions
What makes Binairo different from Sudoku?
Binairo uses only two symbols (0 and 1) instead of the digits 1-9. There are no boxes or regions. The core constraints are preventing three consecutive identical digits, maintaining equal counts of 0s and 1s in each line, and ensuring all rows are distinct from each other (and all columns are distinct from each other). The logic feels closer to binary reasoning than Sudoku's elimination patterns.
What are other names for Binairo?
Binairo is also known as Takuzu and Binary Puzzle. All three names refer to the same puzzle type with identical rules. Takuzu is the original Japanese name, while Binairo and Binary Puzzle are common in English-speaking regions.
Do Binairo puzzles have unique solutions?
Yes. Every Binairo puzzle on PencilGrid has exactly one solution. Our generator guarantees uniqueness and ensures all puzzles are solvable through logic alone, with no guessing required.
Is PencilGrid Binairo completely free?
Yes, all Binairo puzzles on PencilGrid are completely free. No account, subscription, or payment required. Play as much as you want.
When does the new daily puzzle become available?
A new daily Binairo puzzle is published every day at midnight UTC. You can complete previous dailies even if you missed them.
Explore More
Play Today's Puzzle
Solve today's daily Binairo and maintain your streak.
Practice Mode
Unlimited puzzles at Easy, Medium, and Hard difficulty levels.
Play Classic Sudoku
Try the traditional 9×9 Sudoku with given digits and no regions.
Play Suguru
Fill irregular regions with unique digits, no two equal numbers touch.