Binary Puzzles Online — Binairo, Takuzu & Tango

The binary puzzle is one of the most elegant logic puzzles ever designed: a grid, two symbols, and a handful of rules that force every cell through pure deduction. Depending on where you first met it, you may know it as Binairo, Takuzu, Binoxxo, or "binary Sudoku" — and its most popular modern incarnation is the Tango Sun & Moon puzzle. On 8tango you can play unlimited free Tango-style binary puzzles in your browser, from quick 4×4 boards to expert 10×10.

The rules of a binary puzzle

• Two symbols: classically 0 and 1 — on 8tango, Suns and Moons (or any icon pair you choose).
• Balance: every row and column contains an equal number of each symbol.
• No triples: three identical symbols can never be adjacent in a row or column.
• Pure logic: a well-made board has exactly one solution, reachable without guessing.

How Tango evolved the classic Binairo

Classic Binairo/Takuzu puzzles start with a scattering of pre-filled cells and rely on the balance and no-triples rules alone, which usually requires larger grids (10×10 and up) for interesting deductions. Tango-style puzzles add two clue types between neighboring cells — "=" (the cells match) and "×" (the cells differ) — which unlock deep, satisfying logic even on compact 6×6 boards. That's the format made famous by LinkedIn's daily Tango puzzle, and the format you can practice without limits here.

Why solvers love the binary family

• One-minute rules, endless depth — you learn it instantly and keep discovering new techniques.
• No arithmetic — unlike Sudoku, there's nothing to count beyond "half and half".
• Fully fair — every 8tango board is mathematically verified to be solvable by logic alone.
• Scales with you — start on 4×4, grow to 10×10, or race the daily leaderboard.

New to this puzzle family? Start with the complete rules & solving guide or the 5-minute beginner's walkthrough, then pick up 10 expert solving strategies.

Binary puzzle FAQ