NineFold Sudoku

Graded by technique, not clue count. Today's daily is free; Pro unlocks every past day, unlimited hints and no ads. One payment, offline, always.

Most Sudoku apps call a puzzle "hard" because it has fewer clues. NineFold grades every puzzle by the hardest technique it actually takes to solve, so Easy stays easy and Evil earns its name.

FIVE HONEST DIFFICULTIES • Easy, Medium, Hard, Expert and Evil, graded by technique, not clue count • From singles up through X-Wings, XY-Wings and coloring • Every puzzle has exactly one solution, reachable by logic alone

A DAILY CHALLENGE, FREE EVERY DAY • One new puzzle a day, the same for every player • Missed a day? NineFold Pro unlocks the whole archive, back to day one

HINTS THAT TEACH • One tap places the next digit • When the next step only rules candidates out, the hint names the technique and shows the pattern on the grid

PLAYS ANYWHERE • Fully offline: no account, no sign-in, no Wi-Fi needed • Your games, stats and streaks are saved on your device

EASY ON THE EYES • Light and dark themes, plus two colorblind-safe palettes • Four extra themes with NineFold Pro: Paper, Forest, Ocean and Midnight • Full VoiceOver and large-text support • Every accessibility feature is free, always

NINEFOLD PRO The free version is supported by ads. NineFold Pro is a single purchase that removes them, makes hints unlimited, unlocks every past daily and adds four extra themes. It's not a subscription, so it never expires.