About Sudoku91

Sudoku91 is a free, ad-free Sudoku web app built for speed and simplicity. No sign-up required - just open and play.

Features

• 5 difficulty levels: Easy, Medium, Hard, Expert, Evil
• 2,000 unique puzzles with guaranteed single solutions
• Auto-save your progress
• Notes mode for pencil marks
• Undo support
• Keyboard shortcuts
• Dark and light themes
• Available in English and Spanish

How It Works

Puzzles are pre-generated offline to ensure quality and unique solutions. Your progress is saved locally in your browser. Solutions are validated server-side - they are never exposed to the client.

Contact

Sudoku91 is a project by 91GameStreet. For questions or feedback, visit 91gamestreet.com.