Sudoku

About the game

Play sudoku online for free — the classic 9×9 number puzzle right in your browser, no sign-up needed. Fill the grid with digits 1 to 9 so that none repeats in any row, column or 3×3 box. Four difficulty levels take you from easy sudoku for beginners up to expert, every grid is freshly generated with a single solution, and the timer never rushes you. Pencil in candidates, let highlighting show the row, column and matching digits, and undo any move. Each game comes with three free hints, and a flawless win earns three stars. Your unfinished game and best time are saved.

How to play:
Sudoku rules are simple: fill all 81 cells so that every row, column and 3×3 box contains the digits 1 to 9 exactly once. Pick a difficulty in the menu: Easy, Medium, Hard or Expert. Select a cell and place a digit. Pencil adds candidate notes, Erase clears a cell, Undo takes a move back and Hint places the correct digit. A mistake is a digit that is not in the solution; three mistakes lose the game. Three free hints per game; more are available for watching an ad.

Desktop: click a cell, keys 1–9 place a digit, arrows or WASD move the selection, Backspace, Delete or 0 erase, N toggles the pencil, H gives a hint, Ctrl+Z undoes.
Phone: tap a cell, then a digit on the bottom panel, and use the Pencil, Erase, Undo and Hint buttons.

logic
numbers
relaxing

Genre: Puzzle — every game of this genre in the catalog

How to play

Sudoku is a number puzzle played on a 9×9 grid split into nine 3×3 boxes. Some cells start filled in, and your job is to complete the rest with digits 1 to 9 so that each digit shows up exactly once in every row, every column and every box. That's the whole rulebook: no math involved, just logic.

Choose a difficulty in the menu before you start. Easy reveals 40 cells and is the natural place to learn sudoku, Medium gives 33, Hard 28, and Expert leaves you only 24 given digits. Your level is remembered, and wins and best times are tracked separately for each one.

Pick a cell and enter a digit. If it doesn't match the solution, it counts as a mistake, and the third mistake ends the game. To play it safe, switch on Pencil and jot down the candidates for a cell — notes never count against you. Undo takes back your last move, Erase clears a cell, and the selected cell's row, column and matching digits are highlighted.

Every grid is freshly generated and has exactly one solution. The timer just keeps track and never forces your hand, so you can play sudoku online free at your own pace. An unfinished game saves itself, and Continue is waiting in the menu next time.

Controls

Computer: click a cell to select it, press 1–9 (numpad works too) to enter a digit, move with the arrows or WASD, erase with Backspace, Delete or 0, N toggles the pencil, H gives a hint, Ctrl+Z undoes.
Phone: tap a cell, then a digit on the bottom panel; the Pencil, Erase, Undo and Hint buttons sit right next to it.

Features

Classic 9×9 sudoku, every grid with a single solution
Four difficulty levels: Easy, Medium, Hard and Expert
Pencil notes that never count as mistakes
Highlighting for the row, column and matching digits
Three free hints per game and unlimited undo
Up to three stars per win — fewer mistakes, more stars
Auto-save, plus best time and win count for every level

Tips

If you're just learning, start on Easy and move up to Hard and Expert once naked singles jump out at you.
Start with the boxes and rows that already show the most digits — empty cells there have fewer options.
Work through the digits one at a time. Take the 1s, check where each box can still fit one, and you'll often find only one spot left.
Look for naked singles: if the row, column and box already rule out eight digits, the cell can only hold the ninth.
When a cell has two or three options, pencil them in, and when you place a digit, clear it from the notes in that row, column and box.
After every digit you place, look around for a newly forced cell — solves usually come in chains.
Don't guess. You only get three mistakes, and your stars depend on them: none earns three stars, one earns two, two earns one.
A hint fills the correct digit into the selected cell, so spend it on the hardest spot rather than the first empty one.

FAQ

How do I play sudoku as a beginner?

Fill the empty cells with digits 1 to 9 so that none repeats in a row, column or 3×3 box. Start where many digits are already shown, and pencil in anything you're unsure of — notes never count as mistakes.

Can I play sudoku online for free without signing up?

Yes. It runs right in your browser on a computer or a phone, with nothing to download and no account to create.

Is there hard sudoku?

Yes. The menu offers four levels: Easy, Medium, Hard and Expert. The higher you go, the fewer digits are given — Expert shows just 24 — but every grid still has exactly one solution.

Are there hints?

Yes, every game comes with three free hints. A hint places the correct digit in the selected cell. Once the free ones run out, any hints you bought are used next, and after that you can get another by watching an ad.