Free Browser Sudoku, Built by Sudoku Nerds
These are the same style of puzzles we ship in our iOS app: generated offline, checked for a unique logical solution, and graded by the number of starting clues. The daily puzzle is identical for every player — solve it, note your time, and challenge a friend to beat it. Beyond classic grids you can now play Thermo and Arrow Sudoku right here in the browser, each in a full 9x9 and a beginner-friendly 6x6 mini. If a variant hooks you, there's a full written guide for every type in our guides library, from first-timer rules to expert techniques.
Want even more? The free Sudoku - Brain Puzzles app for iPhone and iPad adds Killer, Sandwich, Jigsaw, Kropki, Diagonal, Little Killer, 6x6 mini variants, and the new Fog of War — 18 game types with smart hints, daily streaks, and iCloud sync.