Sudoku online: free daily and unlimited puzzles
Fresh 9×9 grids with one solution each. Daily puzzle plus easy to hard.
Part of the AllFun Daily — your streak: 0 days.
Every grid here is generated on the spot and checked to have exactly one solution, so you never need to guess. Pick Easy, Medium or Hard for unlimited play, or take on the Daily puzzle — the same grid for every player, every day.
How to play Sudoku
- Fill each empty square with a digit from 1 to 9.
- Every row must contain each digit once.
- Every column must contain each digit once.
- Every 3×3 box must contain each digit once.
- Tap a square, then a number. Turn on Notes to pencil in candidates.
Tips and strategy
- Scan for 'hidden singles': a digit that can only go in one square of a row, column or box.
- Work the most crowded rows and boxes first — fewer gaps mean fewer options.
- Use notes on harder grids; when two squares in a unit share the same two candidates, those digits can be removed elsewhere in that unit.
- If you're stuck, switch digits: look for every place a 7 could go before moving to 8.
About the game
The modern number-place puzzle was popularized in puzzle magazines in the late 1970s and spread worldwide in the 2000s. Our generator builds a complete valid grid, then removes numbers one by one — only keeping a removal if the puzzle still has a single solution.
Frequently asked questions
How is difficulty decided?
By how many starting numbers remain: about 40 on Easy, 32 on Medium and 27 on Hard. Fewer clues usually means more advanced techniques.
Does the daily puzzle save my progress?
Yes, on this device. Close the tab and come back — your entries will still be there today.
What do pink numbers mean?
A pink number conflicts with the solution. Use Check to see how many squares are wrong.
Can I play with a keyboard?
Yes. Arrow keys move, 1–9 enter digits, Backspace erases and N toggles notes.
