Play Binairo (Takuzu) Online

A row of six boxes holds exactly three zeros and three ones. That simple count turns every blank into a deduction about neighboring digits, columns and duplicate patterns. Binairo, also called Takuzu, replaces arithmetic with a small set of binary constraints. Start the six by six board here and try completing a row before comparing it with the other five.

1. Read the given zeros and ones; the gray cells cannot change.
2. Click an empty white cell once to enter 0, again for 1 and a third time to clear it.
3. Count zeros and ones in each row and column as you work.
4. Check for three identical digits in succession in either direction.
5. Compare finished rows and columns to avoid duplicates.
6. Finish every cell while satisfying all four rules. Reset the board if you want a fresh attempt.
7. Start by identifying the gray givens and leaving them unchanged. Work across a line with two matching neighboring digits before you fill an isolated space. On a six-cell row, reaching three copies of one digit settles every other position at once. Return to the corresponding columns after each row decision so a local improvement does not create a vertical triple.
8. If a line looks complete but the puzzle does not finish, check its opposite direction before changing any cell. A horizontal pattern may be fine while the same cells form three consecutive zeros vertically. Next compare each full row against the other rows, then repeat that comparison for columns. This orderly final pass finds rule violations faster than changing digits at random.

• Each six-cell row and column contains three 0s and three 1s.
• Neither three 0s nor three 1s may appear consecutively.
• No two finished rows may match. The same uniqueness rule applies to columns.
• The board accepts any complete arrangement that satisfies the rules and respects the fixed clues.
• Uniqueness is a separate rule from balance. Two rows can each contain three of both digits and avoid triples yet still be identical. Compare completed lines as strings. If two rows differ only at a pair of unknown positions, those positions cannot receive the same pattern. Columns deserve the same comparison, even when their numbers look balanced.

• When you see 00, place 1 on either side if space allows. The same technique works for 11.
• A 0?0 forces a 1 in the center. Write the complementary digit before guessing elsewhere.
• When a row already has three ones, fill every remaining opening with zero.
• Compare two almost identical rows. The last pair of vacancies often must differ.
• Do not stop at rows: a legal row can still create a forbidden triple in a column.

• Sudoku: Practice the standard number-placement rules before trying a variant.
• Hitori: Compare how a related puzzle uses regions, paths or tile placement.
• Norinori: Compare how a related puzzle uses regions, paths or tile placement.

• Every cell has only two options, so short deductions produce quick progress.
• The uniqueness check rewards looking across the entire board.
• A wrong digit stays editable; you can test a line and then undo it by clicking.
• Binairo gives a short feedback loop because each mark has just two possible values. The challenge comes from the interaction of four tests, not a complicated control scheme. You can clear a mistake with a third click and return to the earliest forced line. The finished grid is checked by its rules, so the visible clues remain the authority.

Play Binairo free in your browser. Start the interactive board above, use its on-screen controls and check the rules below when a deduction gets stuck. No download or account is needed.

Try another round of Binairo on the board above. Start with the most constrained part of the grid, test each move against the stated rules, and use the reset control to try a new approach.

• Takuzu rules and background