Sudomnia
A Sudoku for Android. Every puzzle is checked to be solvable by reasoning alone — no guessing, ever.
No puzzle needs guessing
Before a puzzle reaches you, Sudomnia solves it the way a person would: hidden and naked singles, locked candidates, naked and hidden pairs and triples, X-Wing, Swordfish, simple colouring, XY-Wing. Never by trying a digit to see what happens. A puzzle that cannot be finished that way is not published to you.
Most generators only check that the solution is unique. We measured our own earlier version: of the puzzles it called hard, 53 % could not be finished by any of those techniques.
Four levels that mean something
The level is the hardest technique the puzzle actually requires, measured on that grid — not a guess from the number of clues.
| Level | What it takes |
|---|---|
| Easy | singles only, at least 36 clues left standing |
| Medium | singles only, dug as deep as uniqueness allows |
| Hard | locked candidates, or a pair or triple |
| Expert | an X-Wing, colouring or an XY-Wing |
Hints that explain themselves
The hint names the technique and the reason — “in box 5 the 7 fits only in cells that also lie in column 3, so it can go from the rest of column 3” — and shows the candidates it strikes out, crossed out in the grid. Only the last press enters a digit, and by then you know why it belongs there.
Nothing leaves your device
The Play build holds no Android permission that lets it do anything — not even internet access. There is no server side: puzzles are generated on the device. No ads, no account, no analytics, no crash reporter.
Get it
- Source, releases and issues: github.com/alramlechner/Sudomnia
- Privacy policy