Sudoku Classic: Logic Puzzles

A free, offline classic sudoku puzzle game, built by me!

Free, offline, and completely ad-free. Endless, freshly generated classic sudoku puzzles. Puzzle difficulty is graded by the logic each puzzle actually requires, not by how many cells start blank.

What's in the app today

✓ Endless classic 9×9 sudoku puzzles generated on the fly

✓ Seven difficulty levels: Casual, Beginner, Easy, Medium, Hard, Expert, Master

✓ Difficulty graded by the logic techniques each puzzle requires

✓ 20+ colour themes — light, dark, high-contrast, sepia and more

✓ Undo, redo, pencil marks and one-tap erase

✓ Highlight matching numbers, rows, columns and boxes

✓ Pause and resume — auto-save picks up exactly where you left off

✓ Statistics for every solve

✓ Left- and right-handed layouts

✓ Full landscape and tablet support

✓ Fully offline

✓ No ads

Difficulty that actually means something

Most sudoku apps grade difficulty by how many cells start empty. My app grades puzzles by what techniques are actually required to solve them. Beginner puzzles use beginner techniques — full houses and naked/hidden singles — and the techniques get harder as the difficulty climbs. Above Beginner you'll start running into naked and hidden pairs, triples and quads. Above that, X-Wings, Y-Wings and swordfish. Expert is genuinely challenging, dipping into uniqueness reasoning, colouring, XY chains and some ALS techniques. The toughest Master puzzles can require Franken and Mutant fish, and the occasional Death Blossom.

If you want to improve your brain and get better at solving classic sudoku puzzles, this is the app for you.

Coming soon

→ Comprehensive tutorials for every solving technique

→ A hint system that teaches the techniques used to reveal answers

→ Auto candidates

→ Daily puzzles

Learning mode is in development

A guided campaign through sudoku solving techniques — from basic scanning and naked singles through X-Wings, swordfish, XY chains and ALS. Most sudoku apps treat the puzzle as a way to fill time. This one wants to help you grow at it.

About

It's just me building this! If you find a bug, want a feature, or have feedback, the support email comes straight to me. Thanks for playing!

Privacy

No personal data is collected. No data is shared with third parties. The app records anonymous performance and crash diagnostics so bugs can be fixed. Nothing is tied to your identity and none of the data is sold in any way. Full details in the Play Store Data Safety section.

Privacy Policy: https://mattlaanvere.github.io/privacy/sudoku