Sudoku

How to play Sudoku

1. Fill the grid so every row, every column, and every 3×3 box holds the digits 1–9 exactly once. The printed clues are fixed; everything else is yours.
2. Tap a cell, then a digit on the pad — or use the keyboard: digits type, arrows move, backspace erases.
3. Thinking in candidates? Switch to the Pencil tool (or press N) to jot small notes in a cell's corner. Placing a real digit tidies that number out of the notes around it automatically.
4. Mistake checking is on by default — a wrong digit shows in red ink, and since every puzzle has exactly one solution, "wrong" is a fact, not a guess. Purists can turn it off with the eye button. Stuck? A hint fills one cell honestly.
5. Pick your page: Easy (40 clues), Medium (34), Hard (30), or Expert (26), with your best clean time saved per difficulty — or play the shared Daily and build a streak. Games auto-save, so a closed tab just means "continue later".

A little background

Sudoku is the newspaper puzzle: retired architect Howard Garns published it as "Number Place" in a 1979 Dell puzzle magazine, Japan's Nikoli picked it up in 1984 and named it sūdoku — "the digits must remain single" — and after Wayne Gould talked The Times of London into printing one in 2004, it spent the next few years next to the crossword in practically every paper on earth. The name was only ever trademarked in Japan, which is why everyone else gets to call it what it is.

This version keeps the folded-newspaper feel — a cream grid, printed clues in ink, your answers in pen, pencil marks in the corners, even the scratch of graphite — and adds what print never could: a guarantee that every puzzle has exactly one solution (the generator proves it before you see the grid), honest mistake checking you can switch off, and a daily puzzle the whole family plays on the same board. Free, no ads, works offline once loaded.