Free Sudoku Online — Works Offline

A clean, free sudoku with no ads and no sign-up. Open the page and play. It works without a connection and installs as an app on your phone, tablet or computer. Four difficulty levels, graded by the techniques you need to solve each puzzle — not by how many cells are empty.

Difficulty graded by technique, not by empty cells

Most sudoku sites estimate difficulty by counting clues. That measure is unreliable: some puzzles with very few clues fall to the simplest techniques. Here, every puzzle runs through a solver that reasons the way a person does. If naked and hidden singles are enough, it's easy. If it takes an X-Wing, it's hard. You pick a level knowing exactly what it will ask of you, from easy sudoku up to expert.

Play anywhere, even without a connection

Your game saves itself on every move: close the tab, come back later, and pick up exactly where you left off — offline included. There's a fresh puzzle every day in the daily sudoku. And if you're starting from zero, the rules are laid out calmly in how to play.