Free Online Sudoku – Play Sudoku Puzzles Easy to Expert with Hints & Notes

Free Online Sudoku

Easy to expert puzzles • Pencil notes • Hints • Auto-save • No sign-up

Level: Medium Mistakes: 0 Time: 00:00

Show mistakes instantly Highlight matching numbers 3-mistake limit (game over)

Keyboard: 1-9 fill • Arrows move • Backspace erase • N notes • Ctrl+Z undo

Play Sudoku Online for Free

This free online Sudoku lets you play unlimited puzzles right in your browser. There is nothing to download and no account to create. Every puzzle is generated on your device and has exactly one solution, so you can always solve it with logic and never need to guess. Choose from four levels: Easy, Medium, Hard and Expert.

How to Play Sudoku

1. The board is a 9×9 grid split into nine 3×3 boxes.
2. Fill every empty cell with a number from 1 to 9.
3. Each row, each column and each 3×3 box must contain every number from 1 to 9 exactly once.
4. Tap a cell, then tap a number (or type it on your keyboard) to fill it in.
5. Turn on Notes to pencil in candidate numbers when you are not sure yet.

Features

• 4 difficulty levels, from relaxing Easy puzzles to tough Expert ones.
• Pencil notes that clear themselves when you place a correct number.
• 3 hints per game, plus unlimited undo.
• Mistake checker and an optional 3-mistake challenge mode.
• Timer and best times saved for each difficulty.
• Auto-save: close the tab and pick up where you left off.
• Works on mobile, tablet and desktop, with full keyboard support.

Sudoku Tips for Beginners

1. Scan for singles

Pick a number and look at each box. If that number can only go in one cell of a box, row or column, place it there.

2. Use notes on harder puzzles

On Hard and Expert, write every candidate number into the empty cells. Look for cells with only one candidate left, or for pairs of cells that share the same two candidates.

3. Never guess

Every puzzle here has a single solution that you can reach by logic alone. If you feel stuck, look at a different row, column or box.

Frequently Asked Questions

Is this Sudoku game really free?

Yes. You can play unlimited Sudoku puzzles for free, with no sign-up and no download.

Does every puzzle have one solution?

Yes. The generator checks every puzzle to make sure it has exactly one valid solution.

Will I lose my game if I close the page?

No. Your game is saved automatically in your browser. Open this page again to continue.

Can I play Sudoku on my phone?

Yes. The board and number pad adjust to fit any screen size, so it works well on phones and tablets.

Puzzles are generated in your browser • Nothing is uploaded • Free forever