Binary No. 19

Sunday, 30 August 2026 · 6×6 · Hard

Ready

Binary No. 19

A grid of noughts and ones, filled in by logic alone. 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 — 3 of each.
  4. No two rows are the same, and no two columns are the same.
0 / 36 cells
00:00
Board
Click a square to cycle it: 0, then 1, then empty again.
Solved Binary
00:00
Your time
This puzzle
6×6 · Hard
11 given · 25 to work out

Every square could be worked out from the ones around it. Nothing in this grid 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 — 3 of each.
  4. No two rows are the same, and no two columns are the same.

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 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.

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