Kakuro
A number crossword — fill every run so it hits its sum with no repeated digit.
How to play Kakuro
Kakuro is a number crossword. Instead of words, you fill the white cells with the digits 1 to 9. The grid is split into runs — unbroken horizontal and vertical lines of white cells — and every run has a target sum, written in the shaded clue cell at its start. The number in the upper-right of a clue cell is the sum for the run going across to its right; the number in the lower-left is the sum for the run going down below it.
Two rules govern every run: the digits must add up to the clue, and no digit repeats within the same run. Tap a white cell, then tap a number to place it. Each puzzle is generated with exactly one solution, reachable by logic alone.
Solving tips
- Start with the tight runs. A two-cell run of 3 can only be 1+2; a 4 can only be 1+3. These "forced" pairs give you a foothold with zero guessing.
- Learn the extremes. A two-cell run of 17 must be 8+9, and 16 must be 7+9. The very high and very low sums have only one combination.
- Cross-reference. Every white cell sits in one across run and one down run. A digit that works for one but is banned by the other is out — that intersection is where Kakuro is solved.
- Track what's used. Because a run can't repeat, once a digit is placed the rest of that run loses it. Combine that with the sum to squeeze out the next cell.
Why Kakuro is satisfying
Kakuro sits right between arithmetic and pure logic. Every move is a small sum, but the real work is deduction — narrowing a cell to one possibility by combining what a run needs with what its crossing run forbids. It has the same clean, no-luck feel as Sudoku, with a little mental arithmetic woven through. If you like Killer Sudoku, Kakuro is the natural next step: it's sums all the way down.
Frequently asked questions
Is Kakuro free here?
Yes, completely free with no sign-up. It runs in your browser and your best time is saved on your device.
Can a digit repeat in a run?
No. Within a single across or down run every digit must be different. The same digit can appear elsewhere in the grid, just not twice in one run.
What do the two numbers in a shaded cell mean?
The number in the upper-right is the sum for the run heading across to the right; the number in the lower-left is the sum for the run heading down. A cell may show one or both.
Does every puzzle have one solution?
Yes. Each board is generated and verified to have exactly one solution, reachable by logic alone.