Printable Binary Diagonals puzzles
Binary Diagonals is a binary puzzle — a board of zeros and ones — with two lines more. Fill in the missing digits so that every row, every column and both long diagonals, marked on the sheet, hold as many zeros as ones, and nowhere three alike stand in a row along any of them. A few digits are given at the start; the rest is the puzzle.
Every day there is a new board in each of three sizes, dealt to everybody alike and solvable without a single guess. Pick a size, print the sheet, and take it wherever a screen would not go — a pen is all it takes.
Today’s sheets
A4, black and white, one puzzle a sheet, with how to play on the last page. No sign-up, nothing to fill in.
A new set every day at midnight UTC.
How to play
Fill every empty cell with a hollow square or a filled one, so that each row, each column and each of the two long diagonals — the lines drawn corner to corner — holds as many of one as of the other.
Never three alike one after another — not in a row, not in a column, and not along either of those two diagonals.
Tap a cell for a filled square, tap again for a hollow one, once more to clear it. The squares the board came with stay put: tap one and they all give a shake, to show which they are.
Shown in red: three of the same kind one after another, and squares a row, column or diagonal has too many of.
Questions people ask
- Is it free?
- Yes. The sheets, the boards on the site and the archive are free, without an account and without advertising. The PDFs are made once a day and anyone may download them.
- How many puzzles are there a day?
- One new board a day at each level — 8 × 8, 10 × 10, and 12 × 12 — the same for everybody, dealt at midnight UTC. Earlier days stay downloadable in the archive below.
- Do I need to sign up?
- No. Every sheet downloads without an account. An account only keeps your online plays and your streak in one place across your devices.
- Does every puzzle have exactly one solution?
- Yes. Every board is checked to have a single solution and to be solvable by reasoning alone — no guessing is ever needed. The solution is not printed; the sheet holds the puzzle and the rules.
- May I hand the sheets out or use them in a classroom?
- Yes — print, photocopy and hand them out as you like, for a class, a club or a waiting room. Only leave the credit line at the foot of the sheet where it is.
Earlier days
No timer. Leave and come back — it’s saved.
Play today’s Binary Diagonals online