SudokuType the clues
Select a cell and type its digit. The cursor moves to the next cell automatically. You can also paste all 81 cells at once, using 0 or a dot for empty cells.
SOLVE ANY SUDOKU
Sudoku Solver
Enter the clues of any Sudoku and get the answer instantly, or one explained step at a time.
SUDOKU SOLVER
Enter your puzzle.
Select a cell and type the clues of your puzzle, then press Solve.
1–9 to enter · 0 or Space for an empty cell · Delete to clear · Arrows to move
◇ No account needed✓ Always free to play◎ Made for your focus
FREE SUDOKU SOLVER
Stuck on a puzzle? Solve it in one click.
From a newspaper, a book, or an app.
Instant answer, or one step at a time.
Validate the puzzle
Check tells you whether your grid has exactly one solution, several solutions, or none. Conflicting clues are highlighted in red so you can fix typing mistakes.
Full answer or a nudge
Solve fills the whole grid in blue. Next Step reveals only one cell and explains why it must hold that digit, so you can keep solving on your own.
HOW THE SOLVER WORKS
Use the solver ↗Logic first, then search
Naked singles
Next Step first looks for an empty cell where only one digit is still possible after checking its row, column, and box.
Hidden singles
If none exists, it looks for a digit that has only one possible place in a row, column, or box.
Complete search
Solve uses a fast backtracking search that always picks the cell with the fewest candidates. It finds the answer to any valid Sudoku in a fraction of a second.
Uniqueness check
The solver keeps searching for a second solution. A proper Sudoku has exactly one, which is why grids with fewer than 17 clues are always flagged.
KEEP PLAYING
More free Sudoku puzzles
Daily SudokuOne shared puzzle a day.Easy Sudoku43 clues, perfect to start.Medium Sudoku36 clues, room to think.Hard Sudoku30 clues, notes recommended.Expert SudokuAbout 25 clues, beyond singles.6×6 SudokuDigits 1 to 6, great for kids.Killer SudokuCages, sums, and pure logic.Printable SudokuPrint or save as PDF.Sudoku StrategiesLearn every solving technique.
GOOD TO KNOWA little clarity
A little clarity
before you play.
The details, without the distractions.
Is the Sudoku solver free?
Yes. The solver is free, needs no account, and runs entirely in your browser. Your grid is never sent to a server.
Can the solver explain the solution?
Yes. Next Step reveals one cell at a time and explains the reason when it is a naked single or a hidden single. When a position needs an advanced technique, it says so and reveals one cell.
What if my puzzle has more than one solution?
Check and Solve tell you. A proper Sudoku has exactly one solution; if yours has several, the solver shows one of them and warns you. This usually means a clue is missing or mistyped.
How do I enter a puzzle quickly?
Type the digits row by row; the cursor advances after each one. Or paste 81 characters into the import box, using 0 or a dot for empty cells.
Can I share a puzzle?
Yes. Copy Link creates a link that opens the solver with your grid already filled in.