Play Master Sudoku Online Free
More Games to Play
About Master Sudoku
Master Sudoku is the standard number puzzle: a 9x9 grid divided into nine boxes, some numbers given, and the job of filling the rest so that every row, column and 3x3 box contains each digit from 1 to 9 exactly once.
There's no arithmetic in it at all — it's pure constraint logic, and every valid puzzle has exactly one solution reachable without guessing.
How to play Master Sudoku
- Select a cell
- Click it
- Enter a number
- Type it or click the number pad
- Notes
- The pencil/notes toggle
- Each row must contain 1 to 9 with no repeats.
- Each column must contain 1 to 9 with no repeats.
- Each 3x3 box must contain 1 to 9 with no repeats.
- Fill every cell to complete the puzzle.
Master Sudoku tips
- Scan for the digit that appears most often on the board — its remaining places are the most constrained.
- Use pencil notes on any cell with more than two candidates.
- Look for a box where a digit can only go in one row or column; that eliminates it elsewhere.
- Never guess — every proper sudoku is solvable by logic alone.
Master Sudoku — questions
What are the rules of sudoku?
Fill the 9x9 grid so every row, every column and every 3x3 box contains the digits 1 to 9 exactly once. There's no arithmetic involved.
Do you ever need to guess?
No — a properly constructed sudoku has a single solution reachable by logic alone. If you feel forced to guess, there's a deduction you haven't spotted.
Does it work on a phone?
Yes — tap a cell and use the number pad. Nothing to install.
- Categories
- Puzzle
- Platform
- Web browser — desktop, mobile, and Chromebook
- Cost
- Free, no download or sign-up