Sudoku

Play Sudoku online free. Solve a unique 9x9 number puzzle with pencil notes, undo, explained hints and browser save/resume. No countdown or sign-up.

Play Sudoku online with a clear nine-by-nine board, pencil notes and as much thinking time as you need. The rule is familiar: fill each row, each column and each three-by-three box with the digits one through nine, using every digit once. Pale numbers are fixed clues. Lavender numbers are your own entries, and highlighted duplicates show where a row, column or box needs another look. There is no countdown and no lives counter, so an uncertain move never ends the puzzle. Every new grid is generated locally and checked for exactly one solution before play. The generator aims for thirty-eight starting clues, although a puzzle can keep additional clues to preserve uniqueness. The actual clue count appears above the board; it is not a measured difficulty rating. Select a cell with your finger or mouse, then use the number pad. On a keyboard, move with the arrow keys and enter a digit directly. Notes mode puts small candidate digits inside an empty cell. Placing a full-size number removes that candidate from neighboring notes, while Undo restores the whole previous edit, including affected notes. When you want help, Hint explains a forced single or a digit that has only one available position in a row, column or box. Read the explanation before choosing whether to place it. If no supported deduction is available, the game says so rather than guessing. Viewing an explained digit marks the solve as guided, even if you undo its placement. Your unfinished puzzle, notes and active time save in this browser when storage is available. Pause stops the clock, as does leaving the tab or switching away from the game. Continue from the saved grid when you return on the same browser. A completed board shows your active solve time and personal fastest for the same clue count and solo or guided format. Different puzzles can vary in difficulty, so these times are personal references rather than public rankings. Start another puzzle from the result panel, or explore a related puzzle game below. Sudoku runs directly in your browser without registration or a download.

Sudoku runs right in your browser on desktop, tablet and phone. There is nothing to download or install, and you don't need an account: press play and start.