About

freesudoku.io is a small Sudoku site built for calm, focused play in the browser — no download required to start.

What you can play

Classic 9×9 Sudoku across Easy through Expert, plus Killer, Diagonal (Sudoku X), Hyper, and Mini 6×6. Daily puzzles share one board per day so everyone solves the same challenge.

How we build it

The focus is a clean board, fast controls (notes, undo, hints, timer), and pages that stay readable on phones and desktops. We keep marketing copy short on purpose — the puzzle comes first.

Learn more

Learn Sudoku — rules and techniques
Privacy — cookies, analytics, and ads
Daily — today's shared puzzle