Takuzu Solver

Takuzu (also known as Binairo or Binary Puzzle) is a logic game based on a grid composed only of 0 and 1. The goal is to complete the grid while following several rules:

— each row and each column must contain the same number of 0 and 1

— more than two identical symbols in a row are not allowed

— two rows or two columns cannot be identical

some cells are already filled at the start and serve as clues.

To solve a Takuzu by hand, first observe the rows and columns containing the most clues. Several simple rules can then help progress:

— if two identical symbols are adjacent, the next cell must contain the opposite symbol

— a pattern such as 0?0 necessarily forces a 1 in the centre

— when a row already contains half of the required 0, all remaining cells must be 1, and vice versa

— two rows or columns can never become identical

These deductions are often sufficient to solve easy or medium difficulty grids without using trial-and-error methods.

For difficult grids, several advanced techniques can be used:

— contradiction analysis, which consists of temporarily testing a value and checking whether it causes a rule violation

— detection of symmetrical or nearly completed configurations

— duplicate anticipation, to prevent two rows or columns from becoming identical

Automatic solvers such as dCode often combine these methods with heuristics to significantly reduce the number of possibilities to explore.

To improve at Takuzu, it is useful to regularly solve grids of increasing difficulty and quickly recognise recurring patterns.

Experienced players often develop visual reflexes that allow immediate identification of certain constraints.

With practice, solving speed increases significantly thanks to memorising common logical patterns.

There are several variants and adaptations of classic Takuzu. Some modify the dimensions of the grid, while others introduce additional logical constraints.

Among the best-known variants:

— replacing the symbols with O and X is a common alternative

— three-dimensional versions, where constraints apply across multiple planes

— hybrid puzzles combining Takuzu rules with those of other logic games

These variants refresh the gameplay while preserving the core principle of binary constraints.

In classic Takuzu, grids almost always use even sizes such as 6x6 or 10x10. This requirement is necessary because each row and each column must contain exactly the same number of 0 and 1.

With an odd-sized grid, this balance becomes impossible since a row would necessarily contain more 0 or more 1. However, some variants adapt the rules by allowing one additional 1 in these rows or columns.