Sudoku Online: Free Puzzles From Easy to Expert
Play sudoku online for free. Every game is a fresh puzzle with exactly one solution, at easy, medium, hard or expert level. Fill each row, column and 3 × 3 box with the numbers 1 to 9. Use pencil notes, ask for a hint when you are stuck, and turn mistake checking on or off.
Quick answer: Tap an empty square, then tap a number (or type 1 to 9). Each row, column and 3 × 3 box must contain every number from 1 to 9 exactly once. Wrong numbers turn red when “Show mistakes” is on.
How to play sudoku
- The grid has 81 squares in nine rows, nine columns and nine 3 × 3 boxes. Some numbers are already filled in.
- Fill the empty squares so that every row, column and box has the digits 1 to 9, with no repeats.
- Turn on Notes to pencil in possible numbers. Notes disappear automatically when you place a number that rules them out.
- Use Hint to reveal a square if you are stuck. On a computer you can use the arrow keys, number keys, N for notes and Backspace to erase.
Sudoku levels
| Level | Given numbers | Who it suits |
|---|---|---|
| Easy | About 40 | Beginners; solvable by spotting singles |
| Medium | About 32 | Regular players |
| Hard | About 28 | Needs notes and pairs |
| Expert | About 24 | Advanced techniques and patience |
Every puzzle is generated fresh and checked by a solver so it has exactly one solution.
Sudoku strategies for beginners
- Scan for singles. Pick a number and look at each box: if only one square can hold it, place it.
- Only choice. If a row, column or box is missing just one number, fill it in.
- Use notes. Write the candidates for tricky squares. When two squares in a unit share the same two candidates (a “naked pair”), those numbers can be removed from the rest of that unit.
- Never guess. A real sudoku can always be solved by logic, so look for a square with only one possible number.
Love number puzzles? Try 2048 or minesweeper. For a word puzzle, play the word search.
FAQ
Are these sudoku puzzles free?
Yes. Play as many as you like with no sign-up and no limit.
What happens if I make a mistake?
With “Show mistakes” on, wrong numbers turn red and the mistake counter goes up. Turn it off for a classic challenge where you only find out at the end.
More free games and tools
See all of them on the QuickOnlineTips free online tools page and the free online games page.