Guide
How to Play Kakuro
Kakuro is a game of sums and elimination. Read the clues, fill each run of white cells with digits 1–9 that add up without repeating, and let the crossing runs decide every cell.
Play KakuroThe objective
Make every run add up to its clue
Kakuro is played on a grid of white cells and shaded clue cells. Every run of white cells — across or down — has a total printed in the shaded cell that starts it. You win when every white cell holds a digit from 1 to 9, every run adds up to its clue, and no run repeats a digit.
Between the first clue and the last digit, the work is deduction: working out which digits a sum allows, then using the run that crosses each cell to narrow it down. The clock only records your time; nothing forces a move, and every puzzle can be solved without guessing.
The game is free, runs in the browser, and needs no account. Open the board when you want to play; use this guide for the rules, the three puzzle sizes, and the habits that solve grids faster.
The deal
Clue cells, runs, and the digits 1–9
Shaded cells with a diagonal line carry two clues: the number at the top-right is the total for the run going across to its right, and the number at the bottom-left is the total for the run going down beneath it. A run stops at the next shaded cell or the edge of the board, and always has at least two cells.
Every puzzle here is generated fresh when you start it and verified by a solver to have exactly one solution. Selecting a white cell highlights both of its runs, and a line above the number pad lists both clues and the digits that can still fit.
Controls
Tap, type, or use the keyboard
Every method fills the same cells. Pick whichever fits the device in your hand.
Board
Tap or click
Select a white cell. The two runs through it light up so you can see both sums at a glance, and the line above the pad shows both clues and which digits can still fit.
Mobile and desktop
Number pad
Tap 1–9 to enter a digit into the selected cell. Tap the same digit again to clear it, or use the eraser. With Notes turned on, the same buttons toggle small pencil marks instead.
Desktop
Keyboard
Arrow keys move between white cells (skipping shaded ones). 1–9 enter a digit, Backspace or Delete clears. N toggles pencil notes, U or Ctrl+Z undoes, H reveals the selected cell, C checks for mistakes, Shift+N starts a new puzzle, and M mutes the sound.
The loop
Four steps you repeat all puzzle
Reading a clue, narrowing the digits, and crossing runs is the whole game.
- 1
Read the clues
Shaded cells hold clues. A number in the top-right of a shaded cell is the target sum for the run of white cells to its right (across). A number in the bottom-left is the target sum for the run of white cells beneath it (down). A run ends at the next shaded cell or the edge of the grid.
- 2
Fill runs with 1–9
Type a digit from 1 to 9 into each white cell so every run adds up to its clue. A digit may not appear twice in the same run, so a run of three cells with a clue of 7 can only be made from 1, 2 and 4. Digits can repeat between different runs.
- 3
Cross-check both directions
Every white cell belongs to two runs — one across and one down — so each digit has to satisfy both sums at once. That overlap is what makes the puzzle solvable: a cell that could be 1, 2 or 4 across but only 2 or 3 down must be 2.
- 4
Solve by logic, never by guessing
Every grid here has exactly one solution and can be solved by deduction. Start where the sums are most restrictive — two-cell runs and extreme totals — pencil in the possible digits, and let the crossing runs eliminate the rest. The last correct digit completes the grid.
Rules
Every rule that decides a digit
The objective
Fill every white cell with a digit from 1 to 9 so that each run of white cells adds up to the clue that starts it. The puzzle is solved the moment the last cell makes every run valid.
Runs and clues
A run is a horizontal or vertical line of at least two white cells, bounded by shaded cells or the grid edge. Its clue sits in the shaded cell immediately to its left (across) or above it (down). One shaded cell can carry two clues, split by a diagonal.
No repeats within a run
Inside a single run, each digit may be used at most once. The same digit is allowed in other runs, including a run that crosses this one. Digits are 1–9 only; there is no zero.
One solution, always
Each puzzle is generated fresh and verified by a solver to have exactly one valid solution, so you never need to guess. If two digits both seem to fit, another crossing run will decide between them.
Mistakes, checks and hints
Repeated digits and completed runs with the wrong sum are flagged in red as you type. The Check button compares your entries against the solution and marks wrong cells. A Hint reveals a cell for you; a run that used hints does not set a best time.
Timer and stats
The clock starts on your first entry and pauses while the tab is hidden. Wins, hint-free wins, win streak, and best hint-free time are tracked for each size on your own device.
Puzzle sizes
Easy, Medium and Hard
The only setting in Kakuro is the size of the grid. Pick it above the board; stats are kept separately for each size, and a new puzzle starts as soon as you switch.
- 01 · 5×5 playing area · runs up to 4 cells
Easy
A compact grid with short runs and plenty of two- and three-cell sums. Ideal for learning how clues and crossings work, and a quick five-minute solve once the common combinations feel familiar.
- 02 · 7×7 playing area · runs up to 5 cells
Medium
A fuller grid where longer runs start to interlock. Expect to lean on pencil notes and on the sum-combination helper to narrow candidates before committing to a digit.
- 03 · 8×8 playing area · runs up to 6 cells
Hard
The largest grid with the longest runs. Many cells stay open for a while, so the solve rewards patient elimination, careful notes, and spotting runs whose sums leave only one possible set of digits.
Unique sums
Totals with only one combination
Because digits cannot repeat in a run, some totals can be made only one way for a given run length. Learn these and you get free starting digits in almost every puzzle.
2 cells
- 31 2
- 41 3
- 167 9
- 178 9
3 cells
- 61 2 3
- 71 2 4
- 236 8 9
- 247 8 9
4 cells
- 101 2 3 4
- 111 2 3 5
- 295 7 8 9
- 306 7 8 9
5 cells
- 151 2 3 4 5
- 161 2 3 4 6
- 344 6 7 8 9
- 355 6 7 8 9
6 cells
- 211 2 3 4 5 6
- 221 2 3 4 5 7
- 383 5 6 7 8 9
- 394 5 6 7 8 9
Common mistakes
Why solvable puzzles get stuck
Guessing instead of eliminating
Every grid here is uniquely solvable by logic, so a guess is never required. If you are choosing between two digits, look at the crossing runs — one of them almost always removes a candidate.
Repeating a digit in a run
It is easy to place a second 3 in a long run when your eye is on the crossing sum. Repeats are flagged in red as you type, but building the habit of scanning the whole run first saves backtracking.
Forgetting a digit cannot be zero
Digits run from 1 to 9. A run of four cells cannot total less than 10 and a run of two cannot total less than 3, which is why clues like 3 and 4 in two cells are so useful.
Over-noting every cell
Filling every cell with every digit turns notes into noise. Note only what the sums actually permit, and update notes after each placement — or use auto-notes to refresh them.
- Learn the unique sums: 3, 4, 16 and 17 in two cells; 6, 7, 23 and 24 in three cells. Each has only one possible set of digits.
- Start with the most constrained runs — the shortest ones and those with the smallest or largest totals — and pencil in what they allow.
- Use the crossing run: if a cell can only be 1 or 2 across and 2 or 3 down, it must be 2.
- Once a run is nearly full, subtract what is placed from the clue to see exactly what the remaining cells must add to.
- Keep notes small: only note digits that are genuinely possible, and let auto-notes refresh them after a big deduction.
- When stuck, look for a run whose clue leaves two possible digit sets that differ by one digit — a cell crossing it may rule that digit out.
- Use Check sparingly. Solving by logic is the point, and a hint-free win is the only run that sets a best time.
Where you can play
Same game on phone and desktop
kakurogame.app runs in any modern browser with no app to install. Progress stays on the device you played on.
Desktop browsers
Chrome, Edge, Firefox, and Safari all run the game with no plugin. Click a cell and type digits, move with the arrow keys, and use single-key shortcuts for notes, undo, hint, and check.
Phones and tablets
The grid and number pad fit on one screen so you can solve one-handed. Tap a cell, then tap a digit. The board scales to the screen and the on-screen controls are sized for thumbs.
Accessibility
The board is exposed as an ARIA grid with labelled cells, every control has a text label, focus rings are visible, and status changes are announced. Text and controls meet WCAG AA contrast.
Offline-friendly and private
Puzzles are generated in your browser and progress is stored in local storage. There is no account, no server-side game state, and nothing to install.
Still stuck on a rule? Read the Kakuro FAQ or jump in and play.
Play Kakuro free