Hard Kakuro puzzles on a 12×12 grid

Hard kakuro puzzles use a 12×12 grid with an 11×11 playing area and runs of up to nine cells, so combinations are wider and pencil marks matter. Every grid is verified to have one solution. No app, no sign-up and nothing to click through before play; it works offline and plays fully from the keyboard.

How to play hard Kakuro

1. Fill each white cell with a digit from 1 to 9 so that each run adds up to its clue.
2. The lower number in a clue cell is for the run to the right; the upper one for the run below.
3. No digit repeats within a run, even in a run of nine.
4. Select a cell to see its two runs, their lengths and what is left.
5. Use Notes (N) for pencil marks; placing a digit removes it from notes in both runs.

Hard kakuro techniques

Hard grids have about 70 to 82 white cells and runs of 2 to 9 cells. Short unique runs still open the grid, but the middle is settled by combining sets and by elimination.

Think in sets, not sums

A long run rarely has one combination, but it often has digits it must or cannot contain. Nine cells always hold 1 to 9. Eight cells summing to 40 miss only the 5; summing to 44, they miss only the 1. Seven cells summing to 28 miss two digits that add to 17, which can only be 8 and 9, so they hold 1 to 7. Write down what is missing, not what is present.

Cross two runs at a cell

List the candidates each run allows and keep only the digits both allow. A cell where across allows 1, 2, 4 and down allows 4, 6, 8 must be 4. The hint names this Crossing runs.

Use leftovers

Once some cells in a run are set, the rest must make the remainder with the unused digits. Watch the panel under the board: a run with 12 left over 2 cells, where 3, 4 and 9 are already used, can only finish with 5 and 7.

Test a candidate

Some Hard grids need a short trial: take a cell with two candidates, assume one, and follow the runs until something breaks. The hint calls this Trial of candidates.

Daily, stats and printables

This page plays 12×12 Hard grids. They take a moment to generate in the background; the empty board shows while you wait.

The timer starts on your first entry and pauses when you switch tabs. Stats per level stay in this browser: played, won, win rate, best and average time. Undo and Redo cover the whole game. The first two hints on a puzzle are free; if ads are switched on later, more hints offer a short ad or a 30-second wait. Wins come with share text, and every puzzle has a code such as A7K3Q that replays it. Kakuro has no daily puzzle or printable sheets.

Plays anywhere, no app, no account

The 12×12 hard kakuro board scrolls or pinch-zooms inside its frame on a phone, and every digit and pencil mark can be entered from the keyboard. Tidy Puzzles runs entirely in your browser: there is no app to install, no account to create and no interstitial before you can play. After the first visit the game also works offline, because each puzzle is generated on your device from a seed. Every board can be played with the keyboard alone, on a phone or a desktop, and your stats and unfinished puzzles stay in this browser rather than on a server.