Play Sudoku Online
A clean, fast sudoku board with notes, hints, undo, and a timer. Pick a difficulty below and start solving — no account needed.
Game Controls
- Select a cell by clicking or tapping it, then choose a number from the pad.
- Notes toggles pencil-mark mode: numbers you press become small candidate notes in the cell.
- Erase clears the selected cell's value and notes.
- Hint fills the selected cell (or the first empty one) with the correct digit.
- Undo / Redo steps backward and forward through your entire move history.
- New Game deals a freshly generated puzzle at the current difficulty.
Keyboard Shortcuts
| Key | Action |
|---|---|
| 1–9 | Place a digit in the selected cell |
| Backspace / Delete | Erase the selected cell |
| Arrow keys | Move between cells |
| N | Toggle notes (pencil) mode |
| H | Get a hint |
| Ctrl+Z / Ctrl+Y | Undo / redo |
How Difficulty Levels Differ
Each level changes how many clues the puzzle starts with — and therefore how deep you have to dig into logic:
- Easy — many clues, solvable with basic scanning.
- Medium — needs candidate notes and simple patterns.
- Hard — few clues, demands advanced techniques.
You can also switch difficulty any time using the pills above the board. Not sure how to start? Read the rules of sudoku first.