🧠 Daily Brain Challenge
Sudoku, Chalk & All
Generate unlimited puzzles instantly. Solve online with built-in error checking or print with solutions. Choose 4×4 for beginners, 6×6 for training, or Classic 9×9 for the full workout.
9x9
Grid setting
∞
Unique puzzles
100%
Free to play
Printable
Answers included
🧩 Solve interactive grid — fill rows, columns & blocks with digits
Click a cell to select, then type or use the keypad below.
Puzzle completion0% accurate
0 of 81 filledNo hints used
⚙️ How to use the custom Sudoku engine
A quick guide to the real-time validation toolkit and grid options.
🎯 Smart assistive features
- Show game timer: tracks your pacing automatically, or switch it off for relaxed play.
- Highlight same numbers: selecting a cell flags matching numbers across the grid.
- Show mistakes: flags input errors instantly so you don't build on a bad guess.
🎛️ Control dashboard
- ✨ New random puzzle: generates a fresh, mathematically valid layout instantly.
- 🔑 Solution key: reveals the full answer grid to check your strategy.
- 🖨 Print puzzle: a clean, ink-friendly layout for solving on paper.
⌨️ Input & hotkeys
Tap any unlocked cell and use keys 1–9 to fill it in. Press Backspace, Delete, or the ❌ Clear button to wipe a cell. Use 🔄 Reset to clear your work while keeping the starting clues.
💡
Tip: start with the 6×6 Intermediate grid before jumping into the Classic 9×9 — it trains your eye for the same logic at a smaller scale.
