Binary No. 50

Wednesday, 30 September 2026 · Nine 6×6 · Medium

Special

Binary No. 50

A special one today: nine 6×6 binary puzzles laid out in a square, which together are one 18×18 binary puzzle as well. The clock starts when you press start — not before.

The rules
  1. Every square holds a 0 or a 1.
  2. Never three of the same next to each other, across or down.
  3. Every row and every column holds as many 0s as 1s — 9 of each.
  4. No two rows are the same, and no two columns are the same.
  5. And every block too. Each of the nine 6×6 blocks inside the heavy lines is a complete puzzle in its own right — all four rules again, within its own six squares. Some squares only come out of the block, and some only out of the whole 18×18 grid.
0 / 324 cells
00:00
Board
Click a square to cycle it: 0, then 1, then empty again.
Solved Binary
00:00
Your time
This puzzle
Nine 6×6 · Medium
101 given · 223 to work out

Nine puzzles and one puzzle at the same time — and every square of it could be worked out from the ones around it. Nothing here needed a guess.

The rules

  1. Every square holds a 0 or a 1.
  2. Never three of the same next to each other, across or down.
  3. Every row and every column holds as many 0s as 1s — 9 of each.
  4. No two rows are the same, and no two columns are the same.
  5. And every block too. Each of the nine 6×6 blocks inside the heavy lines is a complete puzzle in its own right — all four rules again, within its own six squares. Some squares only come out of the block, and some only out of the whole 18×18 grid.

Click a square to cycle it through 0, 1 and empty. The squares that were filled in for you are fixed and cannot be changed. You can also move around with the arrow keys and press 0 or 1. Finish a whole row or column, or one whole block and it flashes once to say whether it is right — nothing else is marked, and the flash leaves no mark behind. Gone wrong further back than you can undo? Clear my squares empties everything you placed and leaves the givens. Every square can be worked out without guessing.

Archive

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