How to play Kakuro
The rules
Kakuro is a crossword with numbers.
- Fill every white cell with a digit from 1 to 9.
- Every run of white cells, across or down, must add up to the number in the black cell before it. The top number belongs to the run across, the bottom one to the run down.
- No digit repeats within a run.
Every puzzle has exactly one solution, and you reach it by logic, without guessing.
How to play here
- Select a cell: click it or use the arrows.
- Digit: keys 1–9 or the number pad.
- Notes: press N or the Notes button.
- Erase: Delete or 0.
- A digit repeated in a run, or a full run with the wrong sum, is marked with diagonal stripes.
Difficulty levels
| Level | Size | What it takes |
|---|---|---|
| Easy | 6×6 | Combinations and single options |
| Medium | 8×8 | + Required digit |
| Hard | 9×9 | + Matching, once or twice |
| Expert | 9×9 | + Matching, three times or more |
Techniques
Combinations
Some sums can be built only one way, and they are worth knowing:
- Two cells: 3 = 1+2, 4 = 1+3, 16 = 7+9, 17 = 8+9.
- Three cells: 6 = 1+2+3, 7 = 1+2+4, 23 = 6+8+9, 24 = 7+8+9.
- Four cells: 10 = 1+2+3+4, 30 = 6+7+8+9.
In such a run, every cell can only hold those digits.
Single option
When a cell’s run across and run down together allow just one digit, that’s the digit.
Required digit
If every possible combination for a run includes a certain digit, and only one cell of the run can take it, it goes there.
Matching
Sometimes a digit appears in a possible combination, but putting it in a particular cell leaves no way to fit the remaining digits into the remaining cells. Then remove it from that cell.
Tips
- Start with the short runs that have the smallest or largest sums.
- Where a “small” run crosses a “large” one, usually only one digit is left.
- Take notes. In Kakuro they help even more than in Sudoku.
FAQ
- Can a digit repeat within a run?
- No. In every horizontal or vertical run, each digit from 1 to 9 appears at most once.
- Is there a new puzzle every day?
- Yes. A new Kakuro is published every day at each of the four levels: easy, medium, hard and expert. Earlier puzzles are in the archive.
- Do I need an account to play?
- No. You play right in your browser, with no sign-up and no cookies. Your progress is saved in your browser.