Play Sudoku Online Free
Fill a 9×9 grid with numbers 1–9 so that every row, column, and 3×3 box contains each digit exactly once.
▶ Open Sudoku in Full ScreenAbout Sudoku
Sudoku is the classic logic puzzle in its full 9×9 form: fill every row, column, and box with the digits 1 through 9, no repeats. There's no guessing required — every solvable puzzle can be worked out through pure deduction.
How to Play Sudoku
Fill the 9×9 grid so each row, column and box has 1-9.
Sudoku Controls
🖱️ Click cell → Type number
Rules
Classic 9×9 Sudoku: fill every row, column, and 3×3 box with the digits 1 through 9, with no repeats in any of the three. Every solvable puzzle here can be worked out through pure logic -- no guessing required.
Puzzle Pool
This implementation ships with a small curated set of easy starter puzzles rather than an endless generator, so you may see a puzzle repeat if you play many rounds back to back.
Checking Your Work
There's no live error-highlighting as you type. You fill in the grid at your own pace and press Check when you're ready, which compares your entire board against the solution at once and tells you whether it's fully correct.
Controls
Click or tap a cell to select it, then click a number 1-9 to fill it in, or the ✕ button to clear it. Your progress saves automatically, so you can close the tab and pick the same puzzle back up later.
Strategy
Scan for a box, row, or column that's missing only one digit first -- those are guaranteed fills. From there, look for cells where only one digit is possible given everything already visible in its row, column, and box.
Common Mistakes
Entering a number without cross-checking it against the row, column, AND box it belongs to -- a placement can look fine in its row while already conflicting in its box. Forgetting that the pre-filled clue cells can't be edited is another common early mix-up.
History
Sudoku's numeral grid traces to Howard Garns's "Number Place," published in the US in 1979. It was popularized in Japan during the 1980s under the name Sudoku ("single number") and became a worldwide puzzle phenomenon in the mid-2000s.
Tips for Sudoku
- If you're new to the operations in Sudoku, try a few problems on paper first -- speed comes with repetition, not shortcuts.
- Estimate before you calculate in Sudoku: a rough sense of the answer helps you catch mistakes quickly.
- A few focused minutes of Sudoku daily builds calculation speed faster than one long, tired session.
Frequently Asked Questions About Sudoku
Does Sudoku tell me if a number is wrong as soon as I enter it?
No -- this version doesn't flag mistakes in real time. Fill in as much of the grid as you like, then press Check to see whether the whole board matches the solution.
Is my Sudoku progress saved?
Yes -- your grid saves automatically as you play, so closing the tab and coming back resumes the same puzzle where you left off.
Is Sudoku free to play?
Yes. Sudoku is 100% free on GameNest World, with no download or account required.
Can I play Sudoku on my phone?
Yes -- tap a cell, then tap a number on the on-screen pad. It works on desktop, tablet, and mobile browsers.