Sudoku
Classic 9x9 Sudoku with three difficulties, pencil notes, hints, conflict highlighting, a mistake counter and a running timer.
About Sudoku
Sudoku is a logic puzzle played on a 9x9 grid split into nine 3x3 boxes. Your goal is to fill every empty square so that each row, each column and each box contains the digits 1 through 9 exactly once. Every puzzle here is freshly generated from a complete valid solution and then carefully carved out so that it has one and only one answer, verified by a solver before you ever see it. Pick Easy, Medium or Hard, jot down candidate notes, and chase a clean solve with no mistakes and your fastest time.
How to play Sudoku
Tap or click an empty cell to select it, then choose a digit from the number pad to fill it. Use Notes mode to pencil in candidates, the Erase button to clear a cell, and Hint if you get stuck. Complete the whole grid correctly to win and try to beat your best time per difficulty.
Controls
Mouse/touch: tap a cell, then tap a number on the pad; use the Notes, Erase, Hint and New buttons. Keyboard: Arrows or WASD move the selected cell, 1-9 enter a number, 0/Backspace erase, N toggles notes, H gives a hint, M mutes.
Tips & tricks
- Start with rows, columns or boxes that already have the most numbers filled in, where only a couple of options remain.
- Turn on Notes mode and pencil in every candidate for tricky cells, then erase them as you eliminate possibilities.
- Look for a digit that can only go in one spot within a box, even if that cell has several other candidates.
- Tap a filled number to highlight every matching digit on the board, which makes spotting the missing ones much faster.
- Save the Hint button for genuine dead ends, since each hint counts against your mistake total.
Frequently asked questions
How do you play Sudoku?
Tap or click an empty cell to select it, then choose a digit from the number pad to fill it. Use Notes mode to pencil in candidates, the Erase button to clear a cell, and Hint if you get stuck. Complete the whole grid correctly to win and try to beat your best time per difficulty.
What are the controls for Sudoku?
Mouse/touch: tap a cell, then tap a number on the pad; use the Notes, Erase, Hint and New buttons. Keyboard: Arrows or WASD move the selected cell, 1-9 enter a number, 0/Backspace erase, N toggles notes, H gives a hint, M mutes.
Is Sudoku free to play online?
It is. Sudoku costs nothing to play here — no account, no app store, no paywall. Just open the page and go.
Can I play Sudoku on mobile?
Yes. Sudoku works in any modern mobile browser with full touch support, so it plays on phones and tablets as well as on a laptop or desktop — nothing to install.
Who made Sudoku?
Sudoku was built in-house by the GameStudioHub team using open web technology (HTML5), which is why it runs instantly without any download.
More free puzzle games
Sudoku is one of many free puzzle games on GameStudioHub. Browse the whole Puzzle collection, or head back to the home page to explore every category.