About Kakuro
Play Kakuro online for free. Fill horizontal and vertical runs of cells so each run sums to the clue shown, using the digits 1–9 with no digit repeated within a single run. It plays like a crossword built entirely from arithmetic.
The Rules
Fill the white cells with digits 1–9 so each run across or down sums to its clue, with no digit repeated in a run.
Step by Step
- Each white run of cells has a clue showing what its digits must sum to.
- No digit can repeat within a single run.
- A cell where a horizontal and vertical run cross must satisfy both runs at once.
- Fill every white cell so all run sums check out to solve the puzzle.
Tips & Strategy
- Short runs (2–3 cells) with distinctive sums usually only fit a handful of digit combinations — learn the common ones.
- Work outward from cells shared by two short runs — they're the most constrained.
- Cross off digits that would force a repeat within a run as you narrow down options.
- A run's minimum possible sum uses its smallest digits (1, 2, 3…) and its maximum uses its largest (9, 8, 7…) — check both bounds before assuming a digit is possible.
Frequently Asked Questions
Is Kakuro like a crossword?
Yes — it has the same grid structure as a crossword, but every clue is a sum instead of a word.
Can the same digit appear twice in a run?
No, digits never repeat within a single run, similar to how Sudoku digits never repeat in a row.
What are common 2-cell run sums to memorize?
Sums like 3, 4, 16, and 17 only have one possible digit pair (1+2, 1+3, 7+9, 8+9). Learning a handful of these makes short runs almost instant to solve.
