N-Doku

N-Doku is Sudoku the way you want it — six board sizes, four difficulty levels, and the tools you actually need while solving. BOARD SIZES FOR EVERY MOOD Play the classic 9×9, warm up on a quick 6×6 or 8×8, or challenge yourself with 10×10, 12×12, or the full 16×16 grid. FOUR DIFFICULTY LEVELS Easy, Medium, Hard, and Extreme — every puzzle is freshly generated and guaranteed solvable. BUILT FOR HOW YOU ACTUALLY SOLVE • Pencil-mark notes for tracking candidates • Number Help highlights numbers already used nearby, so you can toggle on the assist you want • Unlimited undo • Pinch-to-zoom and pan on larger boards • Pause anytime — your puzzle and progress are saved automatically, even if you close the app TRACK YOUR PROGRESS A live timer and per-size, per-difficulty best times keep you coming back to beat your record. DESIGNED TO GET OUT OF YOUR WAY A clean, distraction-free board with clear box shading, light and dark mode, and full support for both portrait and landscape. Available in English, Spanish, German, Italian, Portuguese, and Hungarian. N-Doku is free to play and supports optional ads.