# Sudoku

> Classic 9×9 number puzzle with four difficulty levels and endless fresh grids.

Play Sudoku online for free: endless new 9×9 puzzles from Easy to Expert, each with one unique solution. Notes, undo and conflict highlights.

- Play: https://mogame.app/en/games/sudoku/
- Genre: Puzzle
- Price: free, no ads, no sign-up, no download
- Platforms: desktop, mobile (web browser)
- Controls: keyboard, mouse, touch
- Online leaderboard: yes
- Released: 2026-10-05
- Last updated: 2026-10-06

## How to play

Fill the 9×9 grid so that every row, every column and every 3×3 box contains each digit from 1 to 9 exactly once. Some cells start filled in; use logic to work out the rest. Select a cell, then pick a number. A wrong number counts as a mistake — after 3 mistakes the puzzle is over. Every puzzle is generated fresh and has exactly one solution, and the difficulty depends on the solving techniques it needs: Easy and Medium only need singles, Hard needs pairs and pointing, and Expert needs X-Wings, Swordfish or XY-Wings.

## Controls

Mouse or tap: select a cell, then a number on the pad. Keyboard: arrow keys to move, 1–9 to enter, Backspace or Delete to erase, N to toggle notes, Z to undo.

## Tips

- Start with the digits that already appear most often — they leave the fewest places to go.
- Turn on notes and pencil in candidates for a box when you get stuck; pairs and triples jump out.
- Tap a number to highlight every copy of it, then scan for the rows and columns it is still missing from.
- Speed counts: every difficulty has its own leaderboard of fastest solve times.

## Frequently asked questions

### Is this Sudoku free?

Yes. Sudoku on MoGame is completely free, runs in your browser and needs no download or sign-up.

### Does every puzzle have only one solution?

Yes. Each grid is generated on the spot and checked by a solver to make sure it has exactly one solution, so it can always be solved by logic.

### How are the difficulty levels decided?

By the techniques you need. Easy can be solved with hidden singles only, Medium also needs naked singles, Hard needs pointing pairs and naked or hidden pairs, and Expert needs advanced moves like X-Wing, Swordfish or XY-Wing.

### How does the leaderboard work?

Every difficulty has its own leaderboard of fastest solve times, in seconds — lower is better. When you finish a puzzle you can choose to save your time (this needs a sign-in). Your best time on each difficulty is also kept on your device.

### Is my game saved?

Yes. Your current puzzle, notes, mistakes and timer are saved in your browser, so you can close the page and continue later.