Rules
Binairo is a square grid you fill with two digits: 0 and 1. On PuzzleKite they wear costumes — 0 is a violet sun , 1 is a teal moon . A few cells are given; the rest are yours.
- Two symbols. Every cell ends up a 0 or a 1. On PuzzleKite, 0 is a violet sun and 1 is a teal moon; givens sit on lavender tiles and never change.
- Never three in a row. At most two of the same symbol may sit side by side, horizontally or vertically.
- Balanced lines. Every row and every column holds as many suns as moons — four of each on an 8×8 board.
- No copycat lines. No two finished rows are the same, and no two finished columns are the same.
The puzzle from this guide, solved. Pick any two rows: they’re never the same.
Every Binairo on PuzzleKite has exactly one solution, and logic alone reaches it. You never need to guess — and a wrong turn turns red the moment it breaks a rule.
First moves
Every first move comes from two rules working together: never three in a row, and half of each symbol per line. On PuzzleKite, Easy grids need nothing else — the three moves below finish them.
Pairs close their flanks Easy
Two equal symbols side by side leave no choice at either end: one more of the same would make three in a row.
Row 2 has two suns in the middle. The cells on both flanks must be moons — 1 0 0 1 — or the row would hold three suns in a row.
Gaps take the opposite Easy
The same rule works with one cell between the pair. Sun, gap, sun can only mean a moon in the middle.
Row 1 reads sun, gap, sun. A sun in the gap would make three in a row, so the middle cell is a moon. Watch for the same pattern standing upright in columns.
Balance fills the rest Easy
A line of 8 holds four suns and four moons. The moment one symbol is used up, every empty cell left in the line is the other one.
Column 1 already has its four moons (ringed). Its one empty cell has to be a sun — and with that, the column is done.
The half depends on the board size. Keep a running count as you fill:
| Board | Of each symbol per line |
|---|---|
| 6×6 | 3 |
| 8×8 | 4 |
| 10×10 | 5 |
Looking ahead Medium
Counting finishes a line once a symbol is used up. Looking one step further settles cells earlier: try each way a line could still finish, and keep what every finish agrees on.
Row 1 below has three moons already, so exactly one more hides among its three empty cells. Suppose the second cell were that moon. The row would have its four, both remaining cells would be suns — and with the given sun beside them, that’s three in a row. The supposition fails, so the second cell is a sun.
Row 1 would have its four moons, so the last two cells would both be suns — three suns in a row.
Every legal finish of the row agrees on it. Place the sun.
You rarely need to list finishes on paper. Ask instead: where can the last moon go? Here it can only live in the right-hand gap, so everything else in the row is a sun. When Hint finds a cell this way, it calls it counting ahead.
Unique lines & chains
Hard grids ask for the fourth rule — no two lines alike — and, once in a while, a short experiment. Both settle cells that pairs, gaps and counting can’t.
A line may not copy another Hard
Two finished rows may never match, and neither may two columns. Late in a grid, that rule decides cells nothing else can.
The habit: when a line is two cells from finished, check both orders against the lines that are already done. If one order copies, the other is the answer.
Short chains Hard
The last resort is a small experiment. Pick an empty cell, suppose one symbol, and follow what the pairs, gaps and counts then force. If the board breaks, the other symbol was right all along.
Row 1 balances, so its last cell is a moon — a pair atop column 7, forcing a sun below it. The forcing runs on until row 5 would need three suns side by side.
The sun breaks the board a few steps later, so the gap is a moon.
Chains stay short here: one supposition, one pass of the easy moves. If you can’t see the break yet, note the cell and move on — a chain is never the first thing to try.
Common mistakes
Almost everyone makes these at first. Each one turns red on PuzzleKite the moment it happens.
A third beside a pair
Two suns feel safe to extend. They’re not: the cells at both ends of a pair are always the opposite symbol.
One symbol too many
A line of 8 holds four of each, even with no three in a row. A fifth moon means one of them is wrong.
Copying a finished line
Both lines can look legal on their own. The rule sits between them: no two rows alike, no two columns alike.
Guessing to get unstuck
Every grid here solves by logic. If you’re tempted to guess, press Hint: it fills one cell and names the idea.
A third sun beside the pair in row 2. Three in a row is the most common slip — Check marks the whole run red.
Five moons in column 1, one over the half. Nothing runs three in a row here, but the line is still broken.
Next steps
Once pairs and gaps feel instant, move up a level. Each one adds a new idea.
- EasyPairs, gaps, balanceTwo alike close their flanks; a full half fills the rest.Play Easy →
- MediumAdd looking aheadTry each finish of a line and keep what they agree on.Play Medium →
- HardAdd unique lines & chainsNo copied rows, and short what-if experiments.Play Hard →
The same ideas carry every size. New here? Start with 6×6 Easy. When 8×8 feels quick, step up to 10×10. Want the board from this guide? Open it in the game and solve it from the start.