Binary puzzles

0:00

Creating a puzzle with exactly one solution…

Continue later

This code contains the puzzle and your progress. Open the link or paste the code on any device to carry on. Nothing is stored on our servers.

How to play

Fill the grid with 0 and 1. Three rules:

  1. No three alike in a row: never three 0s or three 1s next to each other, across or down.
  2. Balanced lines: every row and column has as many 0s as 1s.
  3. No twins: no two rows are the same, and no two columns are the same.

Binary puzzles are also known as takuzu or binairo. Every puzzle on PuzzleSheets has exactly one solution, checked by a solver, and you can always reach it by logic.

Sizes and difficulty

Pick a size from 6×6 to 14×14. Difficulty is about which reasoning you need:

  • Easy: pairs, gaps and counting are enough.
  • Medium: sometimes you have to think about how a whole line can be completed.
  • Hard: whole-line reasoning comes up often.
  • Expert: you will also need the “no twins” rule.

Tips

  1. Pairs: two equal digits side by side are always surrounded by the other digit (00 becomes 1001).
  2. Gaps: a gap between two equal digits gets the other digit (0_0 becomes 010).
  3. Count: once a line has all its 0s, the rest are 1s, and the other way round.
  4. Twins: if a nearly full line could become a copy of a finished line, its last two cells must be the other way round.

Using the player

  • Tap a cell, then 0 or 1, or type 0 and 1 on a keyboard.
  • Highlight conflicts shows three alike, too many of one digit, and twin lines.
  • Your progress is saved on this device. Save code / Continue later lets you carry on elsewhere.

Printing

Print 1, 2 or 4 puzzles per page on A4 or US Letter, with an optional answer key.