This Sudoku never runs out of puzzles. Every board is generated fresh with exactly one solution, ready in a couple of seconds.
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Filling the grid
- 1–9 place a number in the selected cell.
- 0 or DEL erase it.
- 2nd toggles notes mode for pencil marks; placing a real number cleans up the affected notes automatically.
- ENTER gives a hint when you're stuck.
Conflicts light up red, and selecting a number highlights everywhere else it appears, two small things that make solving on a small screen comfortable.
Difficulties that mean something
EASY, MEDIUM, HARD, and EXPERT scale roughly from 46 starting clues down to 26. EASY and MEDIUM stay solvable with basic logic, no advanced techniques, so they're genuinely gentle rather than randomly easy.
A timer runs while you solve. The calculator saves your best hint-free time and your win count for each difficulty.