Free Online Sudoku – No Ads, No Sign-Up
Play unlimited sudoku puzzles online — free, no sign-up, no downloads. Works on your phone, tablet, and computer. Your progress is saved automatically in your browser.
Choose Your Difficulty
Easy Sudoku
Plenty of starting numbers. Perfect if you are new to sudoku or want a relaxing puzzle.
Play easy sudoku →Medium Sudoku
A balanced challenge that requires basic techniques like naked pairs and pointing pairs.
Play medium sudoku →Hard Sudoku
Fewer clues and tougher logic. For players who know advanced patterns like X-Wing.
Play hard sudoku →Daily Sudoku
A new challenge every day. Same puzzle for everyone, difficulty ramps up through the week.
Play today's puzzle →New to Sudoku?
Learn the rules in two minutes and pick up the core solving techniques.
Read the rules →What Is Sudoku?
Sudoku is a logic-based number puzzle played on a 9×9 grid divided into nine 3×3 boxes. The goal is to fill every row, every column, and every 3×3 box with the digits 1–9, without repeating any digit within a unit. Every puzzle on Sudoku Whale is generated with a verified unique solution — there is always exactly one correct answer, and it can always be reached by logic alone.
Built-in Features
- Notes mode — pencil in candidate numbers just like on paper.
- Mistake highlighting — wrong entries are flagged immediately.
- Unlimited hints, undo and redo — experiment without fear.
- Timer and mistake counter — track how fast and how accurately you solve.
- Mobile-first design — a comfortable thumb-friendly number pad on any screen.
- Keyboard support — arrows to move, 1–9 to fill,
Nfor notes,Ctrl+Zto undo. - No ads in the game — solve without pop-ups or interruptions.
Ready for a bigger challenge? Learn new tactics on our sudoku strategies page, or jump straight into playing sudoku online.