Lumen Sudoku

New puzzle every day. Classic packs from the world's hardest sudoku. Three board sizes, three difficulties. No ads, ever.

Lumen Sudoku is a clean, focused Sudoku app built around one idea: no noise.

No ads. No pop-ups. No dark patterns. Just puzzles.

DAILY PUZZLE A new puzzle lands every morning. Your difficulty adapts to your skill level. Beginner gets gentle Easy puzzles, Expert gets a Hard puzzle every day with no exceptions. Solve them back to back and build your streak. Miss a day and you start fresh.

PUZZLE PACKS Work through curated sets of famous puzzles with their own stories. The Hall of Fame pack is free and includes five of the most celebrated Sudoku puzzles ever published — including Arto Inkala's AI Escargot, which he spent three months designing and rated 11 out of 10.

More packs are coming.

QUICK PLAY Tap Quick Play and get a randomly generated puzzle in any size and difficulty in under a second. 4×4 for a two-minute break, 6×6 for something in-between, 9×9 for the full experience.

DIFFICULTY THAT MEANS SOMETHING Easy, Medium, and Hard are calibrated by the solving techniques a puzzle requires — not just clue count. Easy uses only naked and hidden singles. Medium adds naked pairs and pointing pairs. Hard adds X-Wing and box-line reduction. No puzzle ever requires guessing.

TOOLS THAT STAY OUT OF YOUR WAY

• Notes mode: pencil in candidates; tap Notes or hold a digit to toggle
• Undo: step back as far as you need
• Hints: reveal the next logical move when you're stuck
• Conflict highlighting: invalid placements turn red immediately
• Timer: optional, unobtrusive, pauses when you leave the app

BUILT FOR iOS

• Full VoiceOver support with descriptive cell labels
• Dynamic Type support at all sizes
• Light and dark mode, designed for both from the start
• Runs entirely offline
• iCloud sync keeps your progress across devices