Kakuro

Kakuro is a free online cross-sum number puzzle you can play instantly in your browser, no download, no account, and no waiting for another player. The grid is a set of white runs separated by black cells: every black cell carries a clue number for the run of white cells it starts, either running right (a row sum) or running down (a column sum). Fill each white cell with a digit from 1 to 9 so that every run's digits are all different from each other and add up to exactly its clue. A cell sits at the crossing of one row-run and one column-run, so getting it right means satisfying both clues at once — that overlap is what makes Kakuro solvable with pure logic instead of guessing. Play through 15 levels that grow the block size and grid from a quick warm-up up to long, digit-heavy runs that take real deduction to crack. A level is solved the instant every run's digits are unique and sum correctly; Try Again deals a fresh grid at the same size any time you want another crack at it.

How to play Kakuro

1. Every black cell carries a clue for the run of white cells it starts: a number running to the right is that row-run's sum, and a number running down is that column-run's sum.
2. Tap a white cell to select it, then tap a digit 1-9 on the keypad to fill it in, or tap ✕ to clear it.
3. The digits in any single run must all be different from each other, and must add up to exactly that run's clue.
4. Every white cell belongs to one row-run and one column-run at the same time, so a correct digit has to satisfy both clues at once — that's the cross-reference that makes the logic work.
5. On desktop, you can also type digits directly and use the arrow keys to move the selected cell without reaching for the mouse.
6. The puzzle is solved the instant every run's digits are unique and sum correctly. A level is one grid; clear it to unlock the next level's larger blocks.

Tips

• Learn the small fixed combinations first: a 2-cell run summing to 3 can only be 1+2, and a 2-cell run summing to 17 can only be 8+9 — clues at the extremes often have just one possible digit set.
• Work the crossing cells first — a cell where a very constrained run (like that 3-clue pair) meets a looser one narrows the looser run down fast.
• If a run's clue equals the maximum possible sum for its length (like 24 for 3 cells: 7+8+9), every digit is forced immediately — always check for these before guessing.
• When you're stuck, scan for cells you've already filled that create a duplicate risk in a still-open run — narrowing what a run *can't* be is often faster than figuring out what it must be.

FAQ