Binary GridPuzzle ยท Brain
How to play Binary Grid
Binary Grid is a logic puzzle on a square grid. Every cell holds a sun or a moon. No more than two of the same symbol may sit side by side, every row and every column holds the same number of suns and moons, and no two rows or two columns are identical. Some cells are already filled in; you work out the rest.
Every puzzle is generated with exactly one solution and can be solved by reasoning alone, never by guessing. Start with the easy patterns: two alike side by side force the cells at both ends, and a line that already has its full share of one symbol is finished with the other. Harder puzzles need you to compare whole lines. Small dots at the end of each row and column count your suns and moons and turn green when a line is full.
Play 60 campaign levels from a quick 4x4 to a sparse 10x10, a new daily puzzle with a streak, or practice any size and difficulty. Hints explain which cell is certain and why, you can undo, check your work, and earn stars for clean solves. Progress and your best times are saved on your device.
Controls
Click a cell: sun, click again: moon, again: empty (right click goes backwards). Arrow keys move, 1 sun, 2 moon, 0 clear, U undo, H hint, P pause, M sound.
Tap a cell to place a sun, tap again for a moon, again to clear. Buttons below the grid: Undo, Hint, Check, Restart.
FAQ
How do I solve a Binary Grid puzzle?
Fill every cell with a sun or a moon so that no three equal symbols touch in a row or column, each row and column has the same number of suns and moons, and no two rows or columns match.
Where do I start?
Look for two matching symbols side by side: both neighbours must be the other symbol. Also look for a symbol, a gap and the same symbol, and for lines that already have half of one kind.
Do I have to guess?
No. Every puzzle has exactly one solution that you can reach by logic. If you are stuck, a hint shows a certain cell and explains the rule behind it.
What are hints and stars?
You start with 5 hints and earn another for each new level you clear. A level gives 3 stars when solved without hints or checks. Watching an optional video gives more hints.
Is Binary Grid free?
Yes. It is free to play in your browser, with no download and no account.
Can I play on my phone?
Yes. It runs on phones, tablets and computers. Tap a cell to place a sun, tap again for a moon, again to clear. Buttons below the grid: Undo, Hint, Check, Restart.