Hints that teach the technique
Stuck? The hint engine finds the easiest of 37 human techniques that applies right now, highlights the cells that prove it, and steps through the reasoning before it places anything.
Free · no ads, ever · works offline
A Sudoku app that teaches you to solve, not just to fill in squares
Every hint names the technique that applies and walks you through the proof before it writes a number. There are no ads anywhere in the app, for anyone, and every mode works with the network switched off.
- 37 solving techniques taught
- 6 difficulty levels
- 47 languages
- 0 ads, on every platform
What you get
An interactive first game
The tutorial is a real board, not a slideshow. It walks you through filling a row, scanning for a number, taking notes, using a hint and recovering from a mistake, one tap at a time.
A library of 36 lessons
Every technique from Naked Single to 3D Medusa has its own lesson, a diagram, and a Try It puzzle that puts you in a position where that exact technique is the next move.
Six honest difficulty levels
Easy, Medium, Hard, Expert, Master and Extreme. Each puzzle is graded by the hardest technique needed to finish it, so the label means the same thing every time.
A Daily Challenge and a streak
A new puzzle every day, a streak that grows while you keep showing up, and a calendar that marks the days you finished and the ones you left half done.
Coach's Report after every game
See what tripped you up: the mistakes you made, the hints you used, a closer look at up to three of those moments on your own board, and the techniques worth reviewing.
Watch your game back
Replay any finished puzzle move by move, notes included, and see where the solve turned.
Zen mode when you want quiet
No timer, mistakes never end the game, and nothing counts toward your stats or streak. Just the grid.
Make it yours
52 themes plus a custom theme builder, six number-pad layouts, adjustable board text size, and light and dark for every theme.
Built for the big screen
Real iPad and Mac layouts with Split View, Stage Manager and hardware keyboard support, not a stretched phone app.
47 languages
Pick your language in Settings, independently of what your device is set to. The lessons, hints and glossary are all translated.
Nothing needs a connection
Puzzles ship with the app. Every mode works on a plane, on the subway, or with the radio off, and your game auto-saves where you left it.
The part most Sudoku apps skip
Most Sudoku apps have one hint: it fills a square and you learn nothing. This one finds the easiest technique that applies to the position in front of you, highlights the cells that prove it, and explains the step in plain language. Everything it teaches in the game is also written up here, for free, whether you install it or not.
How to play Sudoku
The rules in a minute, then the two moves that finish most Easy grids.
Start hereAll 37 techniques
From Naked Single to 3D Medusa, in the order the game teaches them, each with a worked board.
Browse the ladderSudoku glossary
Candidate, unit, strong link, fin, pivot: 31 terms in plain language.
Look up a termWhat makes a puzzle hard
Why clue count is a bad measure, and what each of the six levels actually asks of you.
See the levelsHow it looks
Why “no ads” is a promise, not a plan
There is no advertising SDK in this app. Not a disabled one, not a subscription-gated one: the code is not there. That means no banner waiting for a connection, no interstitial between puzzles, no rewarded video offering you a hint, and no tracking pixel following you out of the app.
It also means removing ads is not something we can sell you, because there is nothing to remove. The optional subscription unlocks premium and custom themes, the Daily Challenge archive and larger hint and mistake allowances. The puzzles, all six difficulty levels, the technique library, the tutorial and the Daily Challenge itself are free.
Questions people ask before installing
Are there really no ads?
None, on any platform, for anyone. There is no advertising SDK in the app at all: no banners, no interstitials between puzzles, no rewarded videos offering a hint. Because there are no ads, removing them is not something the subscription sells you.
Does it work offline?
Completely. Puzzles are generated ahead of time and ship inside the app, so every difficulty level, the Daily Challenge, the technique library and the tutorial all work with the network switched off. Leaderboards and achievement syncing are the only things that need a connection.
Is it free?
Yes. Downloading and playing is free, including all six difficulty levels, the Daily Challenge, the interactive tutorial and every technique lesson. An optional subscription adds premium and custom themes, the Daily Challenge archive, and larger hint and mistake allowances.
How are the hints different?
A hint does not just reveal a number. It finds the easiest of 37 human solving techniques that applies to your exact position, highlights the cells that prove it, and steps through the reasoning in plain language before placing anything. If you use one, the Coach's Report afterwards tells you which technique to review.
How is difficulty decided?
By the hardest technique the app's hint engine needs to finish it, not by how many numbers it starts with. The engine solves every puzzle one step at a time, always taking the easiest step that works, and the puzzle is filed under the hardest step that solve required. The six levels are explained here.
Which devices does it run on?
iPhone, iPad and Apple silicon Macs through the App Store, and Android phones and tablets through Google Play. The iPad and Mac versions have their own layouts, with Split View, Stage Manager and hardware keyboard support.