Sudoku - How to Play & Solving Tips
The rules are simple: fill the 9x9 grid so every row, column, and 3x3 box contains the digits 1-9 exactly once. This free Sudoku game has four difficulty levels — Easy, Medium, Hard, and a genuinely tough Expert mode with only 20 starting clues and a verified unique solution, so it's a real step up once the lower difficulties feel too easy.
Use the Notes (pencil-mark) mode to jot down candidate numbers in a cell before committing, and let conflict highlighting flag any row/column/box clash instantly so mistakes get caught early instead of unraveling the whole grid later. A built-in timer and best-time tracker make it easy to see yourself improving across sessions.
Play Sudoku online free with no download and no sign-up — pick your difficulty and start solving, whether you're working through Easy puzzles for a quick break or grinding Expert for a real logic challenge.
Want a fresh challenge every day? Play the Daily Sudoku, the same puzzle for everyone, and build a streak. Prefer paper? Get our free printable sudoku with answers.
How to Play Sudoku: Step by Step
- Choose Easy, Medium, Hard or Expert.
- Tap an empty cell, then choose a number from 1 to 9.
- Each row, column and 3x3 box must contain 1 to 9 exactly once.
- Turn on Notes to write small candidate numbers in a cell.
- Clashes are highlighted, so you can fix mistakes right away.
Sudoku Tips for Beginners
- Start with the number that already appears most often on the grid.
- Scan each 3x3 box to see where a missing number can go.
- Look for cells with only one possible number.
- Use Notes on harder puzzles instead of guessing.
- If two cells in a row can only hold the same two numbers, remove those numbers from the rest of that row.
Accessible Sudoku
Your puzzle saves itself as you play, so you can close the page and finish later. Undo takes back your last move, and each number button shows how many of that number are still left to place.
This Sudoku works with screen readers such as TalkBack on Android. Every square is a labeled button that reads its row, column and number, the number pad uses real buttons, and a Number first option above the board lets you choose a number once and then double tap every square where it goes. Every move is read out: correct, wrong, notes, hints and the final result. On a keyboard, use the arrow keys to move, 1 to 9 to enter a number, Backspace to clear and N to turn notes on or off. Screen reader support in this game is still being tested on phones, so some parts may not work smoothly with TalkBack yet.
Sudoku FAQ
Which level should I start with?
Start with Easy. Move up when you finish without mistakes.
How hard is Expert?
Expert starts with only 20 clues and always has one unique solution.
Does it track my time?
Yes. There is a timer and a best-time record.
Want to improve faster? Read our Sudoku strategy guide, or see all 19 free games.