About Sudoku Master
Sudoku Master is a free Sudoku game you can play right in your browser — no install required. Every puzzle is generated with a unique solution, and your data is stored only on your own device.
Key Features
- Four difficulty levels — Easy, Medium, Hard, and Expert — with unlimited freshly generated puzzles
- Notes (pencil) mode for jotting down candidate numbers in a cell
- Hints that reveal a cell you can logically confirm
- Mistake-check toggle — instantly spot numbers that break the rules
- An elapsed-time timer with pause
- Daily Puzzle — the whole world tackles the same challenge
- Best times and completion counts saved per difficulty, with automatic resume of an in-progress game
- Light and dark themes, offline support, and 11 languages
How to Play
- Click an empty cell to select it, then enter a number using the number pad or your keyboard (1–9).
- Turn on Notes mode to jot down multiple candidate numbers in a single cell.
- Matching numbers and the related row, column, and box are highlighted automatically to help you avoid mistakes.
- Stuck? Use a hint to reveal a cell, or undo to step back.
- Fill all 9 rows, columns, and 3×3 boxes with 1–9 with no repeats to complete the puzzle.
Frequently Asked Questions
What are the rules of Sudoku?
Fill the 9×9 grid with the numbers 1–9 so that no number repeats within any row, column, or 3×3 box.
Is it really free?
Yes — every feature is free to use, with no sign-up or installation required.
Are the generated puzzles always solvable?
Every puzzle is verified to have exactly one solution, so it can always be solved by logic alone, with no guessing.
Where are my records saved?
Your progress and records are stored only in your browser (localStorage), not on a server. They'll reset if you switch devices.
What is the Daily Puzzle?
It's generated based on the date, so everyone around the world solves the same puzzle on the same day.
Can I play without an internet connection?
Once you've visited the site, you can keep playing offline.