Killer Sudoku: No Coins

🧩 Classic killer sudoku, and not one board in it sits behind a wall.

Fill the 9×9 grid so that every row, every column and every 3×3 box holds 1 to 9, once each. On top of that come the cages: the cells of a cage add up to the small number in its corner, and a digit never repeats inside the same cage. That is the whole game.

📺 THE ADS NEVER CUT INTO A PUZZLE
Not once. An ad can only appear when a puzzle is already over — never while you are thinking, never between two digits, never on a timer. It is the thing players complain about most in puzzle apps, and it does not happen here.

🔑 EVERYTHING IS OPEN FROM THE FIRST LAUNCH
12 boards: three cage styles — small, mixed and large — across four difficulties from Easy to Expert, all playable right now. No coins to save up, no subscription, no daily limit, nothing to unlock. Expert large cages are not the reward for paying: they are just the hard ones.

✅ EVERY PUZZLE HAS EXACTLY ONE SOLUTION
Not one we hope for: a solver checks every board that is generated and throws away any board that has two. So you never have to guess, and when you are stuck, the puzzle is not the thing that is broken.

💡 HINTS THAT EXPLAIN THE DEDUCTION
A hint here does not hand you a cell. It names the rule — a cage of two that adds to 4 can only be 1 and 3, a row that adds to 45 and leaves one cell empty, two cells sharing the same two candidates — so next time you find it yourself. And the basic hint is free, always.

📅 DAILY CHALLENGE
A new board every day, the same one for everybody, with its own cage style. Keep the streak going. The stars it pays are the only currency in this game, and all they buy is board colours.

✏️ NOTES THAT KEEP UP
Pencil candidates into a 3×3 grid inside each cell, every digit always in the same corner. Write a digit and the notes it rules out clear themselves. The keypad counts how many of each digit are still missing.

👆 MADE FOR THE THUMB
Tap a cell, tap a digit. One switch turns the keypad into notes. Undo, erase and check are one tap away. Portrait, one hand, no menus in the way.

📴 Works offline, with no account and no sign-up.

🌍 14 languages.