What we make
Sudoku - Brain Puzzles is a free iOS app with 27 Sudoku variants — Classic 9x9, Killer, Sandwich, Diagonal, Jigsaw, Kropki, Thermo, Arrow, Little Killer, Fog of War, Skyscraper, Anti-Knight, Windoku, Odd/Even, Column Indexer, Mega Sudoku 16x16, and a 6x6 Mini version of most of them. Thirteen of the 27 are free, the app is localised into 12 languages, and it runs on iOS 17.6 and later. It first shipped in January 2026 and is on version 1.2.4.
This website is the other half of the project. It hosts a free browser Sudoku — a daily 9x9, Mega Sudoku 16x16, and Thermo and Arrow puzzles in both 9x9 and 6x6, with no signup and no account — and a guide for every variant plus a library of named solving techniques, from naked singles to Swordfish.
Who builds it
Sudoku - Brain Puzzles is designed and developed by Dongyang Gao, an independent developer. There is no team behind the support inbox — the person who writes the code reads the mail. That is slower than a support desk, and it is also why bug reports tend to turn into a release rather than a ticket number.
What we care about
Hints should teach, not just fill in a square
Every hint in the app names the technique it used — "hidden single in box 4", not a silent digit. If a hint does not teach you the pattern, it has only postponed the moment you get stuck again.
A variant is worth nothing without its rules
Exotic Sudoku variants are usually explained in a sentence and a shrug. Each variant we ship gets a written guide on this site — the rule stated plainly, a worked example, and the traps that catch people the first time — free, whether or not you ever install the app.
Nobody needs an account to solve a puzzle
The browser puzzles need no signup, no email, and no login. This site sets no cookies and loads no analytics or advertising scripts. What the app itself stores is set out in the privacy policy.
The facts
- DeveloperDongyang Gao
- AppSudoku - Brain Puzzles
- PlatformiPhone and iPad, iOS 17.6+
- Current version1.2.4
- Variants27 (13 free)
- Languages12
- PriceFree, optional subscription
- Website puzzlesFree, no signup
- Contact[email protected]
Get in touch
Questions, bug reports, a variant you would like to see built, or a mistake in one of the guides — write to [email protected]. Replies usually take a day or two. The support page answers the questions that come up most often.
Try it for yourself
27 variants, hints that name the technique they used, and a daily challenge. Free on iPhone and iPad.
Download on the App Store