Sudoku

You're given a partly filled 9×9 grid. Place digits so that each row, each column and each of the nine 3×3 boxes contains every number from 1 to 9 with no repeats. Logic alone solves every puzzle, no guessing required.

• Each row must contain 1–9 with no duplicates
• Each column must contain 1–9 with no duplicates
• Each 3×3 box must contain 1–9 with no duplicates
• Given clue cells are fixed; the puzzle is done when the grid is full and valid

• Desktop: click a cell and type 1–9 (Backspace clears); arrow keys move, N toggles notes, H takes a hint. Undo, Erase, Notes and Hint buttons plus a number pad.
• Phone & tablet: tap a cell, then tap a digit on the pad; use Notes to pencil in candidates and Erase to clear.

• Four difficulties: Easy, Medium, Hard and Expert
• Daily puzzle shared by everyone, plus endless Practice
• Pencil-note mode, undo, hints and a live mistake counter

• Scan for cells where only one digit can legally fit, and lock those in first
• Use Notes to pencil candidate digits into tricky cells before committing
• Check the pad's remaining counts, a digit used eight times has just one spot left to find

Sudoku is the classic number-placement logic puzzle. This is an original, free browser version with four difficulty levels, pencil notes, hints and daily and practice puzzles, each guaranteed to have a single solution.

A free, original browser game on PlayPendium. No download, no install.