Easy
Warm up your mind
About 40 given cells — great for beginners.
PlayClassic
Classic Sudoku
Play free classic Sudoku online with easy, medium, hard, expert, and master puzzles. No download or sign-up required. Works smoothly on desktop, tablet, and phone.
Medium
The perfect balance
About 32 given cells — steady logical flow.
PlayHard
Focus and patience
About 26 given cells — sharper deduction.
PlayExpert
Master your technique
About 22 given cells — advanced solving patterns.
PlayMaster
Peak challenge mode
Minimal givens for deep, uninterrupted focus.
PlayHell Mode
Five brutal Killer Sudoku tiers with cage sums — master starts blank, like expert Killer Sudoku elsewhere.
Explore hell modeHow to play this board
This page opens a classic 9×9 Sudoku puzzle in your browser. Select a cell, enter a digit from 1–9, and keep every row, column, and 3×3 box unique. Use notes for candidates, undo to reverse a move, and hints when you want a gentle nudge.
Difficulty on Sudoku Hot
Easy grids start with more givens so beginners can learn scanning. Medium and Hard remove clues and introduce longer logic chains. Expert and Master leave fewer anchors, so pencil marks and structured elimination matter more.
Useful tools while you solve
Notes store candidate digits inside a cell. Undo walks back recent moves without restarting. Hints reveal a logical next step when you are stuck. You can also open Print to take the current style of puzzle onto paper.
- New to Sudoku? Read How to Play first, then return here on Easy.
- Want Killer cages? Switch to Hell Mode for sum-based puzzles.
- Prefer offline sheets? Use Printable Sudoku to generate a packet.
Sudoku FAQ
How do you play Sudoku?
Fill a 9×9 grid so every row, column, and 3×3 box contains each digit from 1 to 9 exactly once. Use the given clues and eliminate impossibilities until only one digit remains for each empty cell.
What is the difference between easy and hard Sudoku?
Easy Sudoku puzzles start with more given digits and leave fewer cells to solve. Hard puzzles have fewer clues and usually require techniques such as hidden singles, pairs, and longer elimination chains.
Do I need to download an app to play on Sudoku Hot?
No. Sudoku Hot runs in your browser on phone, tablet, or desktop. Progress and preferences can stay on your device without creating an account.
What are pencil marks (notes)?
Notes are small candidate digits you write in a cell while you still have more than one possibility. They help track options until logic proves which digit belongs there.
Is guessing allowed?
You can enter any digit, but high-quality Sudoku puzzles are designed to be solved by pure logic. Guessing often creates contradictions later and trains weaker habits.
How is Killer Sudoku different?
Killer Sudoku keeps classic row, column, and box rules, then adds cages with sum clues. Digits inside a cage must add to the clue and cannot repeat inside that cage.