Kakuro
About Kakuro
Kakuro is the crossword's mathematical cousin — a cross-sums puzzle that swaps letters for the digits 1 to 9 and clues for target totals. Every horizontal and vertical run of white cells carries a sum it must add up to, printed in the split black cell at its head, and the one rule that gives the puzzle its bite is that a digit can never repeat inside a single run. That single constraint is also your best weapon: a two-cell run summing to 3 can only be 1 and 2, a 16 across two cells can only be 7 and 9, and those forced pairs cascade through the crossings until the grid unlocks. Like Sudoku it is pure logic with exactly one solution and never a guess required, but the sums give it a different, more arithmetical flavour — you are constantly asking not just "what fits here" but "what set of different digits makes this total." This version hands you the classic solving aids: pencil notes for candidates, a combo helper that lists the digit sets for any run, and a pad that dims digits already used in your run so the no-repeat rule teaches itself. Sixteen hand-checked puzzles climb from gentle 5×5 grids to expert boards. Free in the browser, best times saved, no sign-up.
How to play
- Fill each empty white cell with a digit from 1 to 9.
- Every horizontal and vertical run of white cells must add up to the clue number for that run.
- No digit may repeat within the same run.
- The clue for an across run sits in the top-right of the black cell to its left; a down-run clue sits in the bottom-left of the black cell above it.
Strategy & tips
- Start with the most constrained runs — a two-cell run summing to 3 can only be 1+2, and a 17 can only be 8+9.
- Use the combo helper: it lists which sets of digits can make a run’s sum in the number of cells it has.
- Work the crossings — a cell shared by an across run and a down run must satisfy both, which often pins it to one digit.
- Pencil in candidates when a cell has a few options, then eliminate as the crossing runs fill in.
- It is pure logic — every puzzle has exactly one solution, so you never need to guess.
FAQ
How is Kakuro different from Sudoku?
Both are no-repeat number logic puzzles, but in Kakuro the clues are sums: each run of white cells must total its clue number, and digits only can’t repeat within a run rather than across a whole row or box.
Can a digit repeat in a run?
No. Within any single across or down run every digit must be different, though the same digit can appear in a different run that crosses it.
Do I have to guess?
Never. Every puzzle here is checked to have exactly one solution reachable by logic, so careful deduction always gets you there.
What does the combo helper do?
For the selected run it shows the possible sets of digits that add up to the clue in that many cells — the classic Kakuro solving aid.
Is it free and account-free?
Yes. Kakuro plays free in your browser with no download and no sign-up. Your best times save locally.