A Free Online Sudoku Game, Built for Focus
intosudoku started from a simple frustration: most Sudoku websites are noisy. Banner ads over the grid, forced accounts, pop-ups between every game. We built the opposite: free Sudoku online that feels like a well-made paper puzzle book and is ready the moment you open the page.
Our approach to Sudoku
Every decision in intosudoku comes down to one question: does this help you solve the puzzle in front of you? That's why the interface is dark and glare-free, why notes mode works exactly like pencil marks on paper, and why the game never interrupts you to ask you to sign in.
What makes intosudoku different from other Sudoku sites
- No account required. Open the Sudoku game and start solving immediately. There is nothing to sign up for.
- No ads between puzzles. Play as many Sudoku grids as you want, back to back.
- Every puzzle has one unique solution. Each grid is generated fresh in your browser and checked so it can be solved by logic alone, with no guessing.
- Your progress is always safe. Autosave means you can close the tab mid-puzzle and pick up exactly where you left off.
- Four difficulty levels. Easy, medium, hard and expert Sudoku, from around 45 given numbers down to as few as 23.
- Personal stats without a login. Track best times, win rate and streaks locally, with an optional display name and never a password.
Runs entirely in your browser
The Sudoku generator, solver and save system all run directly in your browser. There's no server processing your moves, and nothing about your gameplay leaves your device unless you choose to send us a message.
New to Sudoku?
Start with our guide on how to play Sudoku. It covers the three rules and the beginner strategies that solve most easy and medium puzzles.
Get in touch
Have feedback, found a bug, or have an idea for a feature? Visit the contact page. We read every message.
Your Next Sudoku Puzzle Is Waiting
Pick a difficulty and start solving free Sudoku online right now. No download, no sign-up.