Kakuro · Cross Sums
A Kakuro trainer that explains every step.
Kakuro Revisited generates puzzles that never need a guess, then walks you to the next deduction in plain words. Ask for a hint, or ask why a digit cannot be there and see the proof.
Play a puzzle Daily puzzle Learn the rules
Free, no account, works offline. Licensed GPL-3.0-or-later.
Why play here
Coach me, in four stages
The next step is broken into where to look, the pattern, the logic and the answer. Learn the technique instead of copying it.
"Why not?" proofs
Choose a candidate and the app follows the forced chain to the exact conflict. Nothing is asserted without a reason.
Every sum, every length
A complete, interactive Sum Combinations Cheat Sheet, from 3 in two cells to 45 in nine.
Five honest levels
Trivial to Extreme. A puzzle is only labeled Easy when the solver reaches it with Easy techniques.
A Daily Puzzle
One date-seeded puzzle a day, the same for everyone, with a share card for the result.
Installs and works offline
A progressive web app. After one visit it runs from your device, with no server and no account.
No guessing, ever
The generator builds a layout, fills it, and keeps a puzzle only when two things are true: it has exactly one solution, and the human solver finishes it using only the techniques in the guides. If a puzzle needs a guess, it is thrown away and another is built.
That is why the difficulty levels mean something. The level comes from the hardest technique the puzzle needs and the length of the solve path, not from how it looks.
See the twelve techniques the solver uses, in the order it tries them.
Tools that teach the technique
Pencil marks keep themselves up to date. The Hints panel lists every technique that is available on the board right now, with a count of how many steps each one gives.
The coach caps itself at the hint level you choose, so an Easy puzzle stays Easy even when you ask for help.
Questions
Is Kakuro the same as Cross Sums?
Yes. Kakuro is also called Cross Sums, Cross Addition or Kakuro, and the rules are the same everywhere: every run of white cells adds up to the clue, digits are 1 to 9 and no digit repeats in a run.
Is Kakuro Revisited free?
Yes. The app is free, needs no account, and the source code is on GitHub under GPL-3.0-or-later. It runs in your browser and stores your games and settings on your own device.
Does it work offline?
Yes. Kakuro Revisited is a progressive web app. After the first visit you can install it and keep playing with no connection, because the generator and the solver run in the browser.
Do I ever have to guess?
No. Every published puzzle is generated with one solution and a complete human solve path. The solver only uses techniques a person can follow, and it never places a digit that is not proven.
What is the AI Coach?
The coach takes the next logical step and explains it in four stages: where to look, the pattern, the logic and the conclusion. You can stop at any stage and try yourself first.
What does the "Why not?" button do?
It places a candidate you choose on a copy of the board, follows the forced moves, and shows the exact conflict that proves the candidate wrong. If the candidate is possible, it says that too.
Is there a daily puzzle?
Yes. The Daily Puzzle is generated from the date, so everyone who plays on the same day gets the same grid, and there is a share card for the result.
Start with a puzzle
Pick a level, or take the Daily Puzzle. The board works on a phone, a tablet and a desktop, and the coach is one tap away.