About Sudoku for Kids

Play Sudoku free online with kid-friendly puzzles, hints, and validation. Start easy and progress to harder grids. Builds logic and number skills for ages 6-12. No ads.

How to use

1. Pick a grid size: Easy 4×4 (numbers 1-4, with 2×2 boxes — perfect for ages 6-8 who are new to logic puzzles), Medium 6×6 (numbers 1-6, with 2×3 boxes — a great bridge), or Hard 9×9 (the classic adult Sudoku, numbers 1-9 with 3×3 boxes).
2. Tap any empty cell to select it, then tap a number from the bottom keypad to place it. The original 'given' numbers are dimmed and locked — you can only edit the blank squares.
3. Follow the one rule: every row, every column, and every bordered box must contain each number exactly once. No row can have two 5s, no column can have two 7s, no box can have two 3s.
4. Turn on Notes mode (the small pencil-marks icon) to write tiny candidate numbers in a cell — a memory aid for tracking which numbers might fit before you commit. This is how every serious solver thinks.
5. Use the easiest technique first — Naked Singles: scan each row, column, and box for a cell where only one number can possibly go, and place it. On Easy 4×4, this alone solves the whole puzzle.
6. Stuck? Tap Hint (you get 3 per game). It fills in one correct number for you, but each hint reduces your win-screen rating, so save them for genuinely impossible spots.
7. Mistakes are highlighted in red right away so kids can self-correct. Sudoku is a pure-logic puzzle — no math is required at any size — and it's a perfect daily 10-minute exercise for executive function development. No sign-up, no ads.

Frequently asked questions

Part of ToolFluency’s library of free online tools for Kids. No account needed, no data leaves your device.