Nine kinds of sudoku, 3,100 hand-graded puzzles, and hints that teach.
BOARDS
• 6×6 — the place to start
• 9×9 — classic, five difficulties
• 16×16 and 25×25 — large grids with pinch-to-zoom
• Jigsaw — irregular regions instead of boxes
• Killer — cages that add up to a total
• Odd/Even — circled squares are even
• Thermo — values rise along each thermometer
• Samurai — five overlapping grids, three difficulties
HINTS THAT EXPLAIN
Stuck? The hint finds one certain move, names the technique and tells you why in a sentence. The Techniques reference covers every strategy with a worked example, so the vocabulary sticks.
DAILY CHALLENGE
The same puzzle for everyone each day, in your choice of four board types. Build a streak.
YOUR WAY
Free input with undo and redo, or guided input. Mistake checking, a mistake limit, large pencil marks or automatic candidates, and a one-tap Continue.
STATISTICS, THEMES, ACCESSIBILITY
Times by board and difficulty, streaks and history. Light, dark and high-contrast themes, reduce motion.
Works offline. No account. No ads.
Learn to solve like an expert. Every hint names the technique and explains it.