Large print binary puzzle, 6 by 6

The rules

• Fill every empty cell with a 0 or a 1.
• No more than two of the same digit may stand next to each other in a row or in a column. Three 0s in a line, or three 1s, are not allowed.
• Every row and every column must hold the same number of 0s and 1s: three of each in this grid.
• No two rows may be identical, and no two columns may be identical.
• Tap a cell to step through empty, 0 and 1. The shaded cells are given.

Three moves that solve every grid here

The first move is the pair. Wherever two equal digits stand side by side, the cells at both ends of the pair must hold the other digit, or there would be three in a line. Two 1s together means a 0 before them and a 0 after them. Look for pairs along every row and down every column before anything else.

The second move is the gap. If two equal digits have exactly one empty cell between them, as in 0, blank, 0, the blank must be the other digit, for the same reason. Gaps are easy to miss, so check for them each time you have filled in a few cells.

The third move is counting. A row of six holds three 0s and three 1s. As soon as a row has its three 1s, every remaining blank in it is a 0, and the other way round. The same goes for columns. On a grid this small, counting finishes most lines once the pairs and gaps have been dealt with.

Go round these three moves in turn. Every puzzle on this page was accepted only after a program completed it with these moves alone, so if you seem to be stuck, there is a pair, a gap or a full count somewhere that has not been used yet. The rule about identical rows is there to make the solution unique; you will seldom need it to make progress.

Tips for printing and playing

• A 0 and a 1 are hard to confuse even at a distance, which makes this puzzle a good choice when small differences between digits are tiring to read.
• On paper, write the 1 as a single straight stroke and the 0 as a full round, so that your own entries are as clear as the printed ones.
• The first level gives about half of the cells. The second gives fewer and takes a little longer.
• Check marks wrong cells without showing the answer. Reveal one fills a single cell.
• If you have never met this puzzle, it is sometimes sold under the names Binairo or Takuzu; the rules are the same.

How these puzzles are made and checked

A separate solver lists every legal line and searches for all grids that fit the given cells. The puzzle is kept only if exactly one grid fits and it is the stored one, and only if the three basic rules, applied again by different code, finish it without a guess.

The puzzle of the day is chosen by the date on your device: puzzle 1 was the puzzle for 1 January 2026, and the number goes up by one each day. More cells given: 366 puzzles, so the same puzzle comes round again after 366 days. Fewer cells given: 366 puzzles, so the same puzzle comes round again after 366 days. Every number stays open in the archive control above the grid. More detail is on the page how the puzzles are made, checked and printed.