CageDoku: Killer Sudoku Puzzle

Killer Sudoku, finally without ads.

CageDoku is a calm, beautiful home for Killer Sudoku and seven more logic-puzzle variants. Every puzzle is solvable by human technique — no guessing, no brute force — and every hint explains the why, not just the digit.

★ No ads. Ever.
No banners, no pop-ups, no forced videos. The daily puzzles are free forever. Pro only adds extras.

★ 8 Sudoku variants in one app
• Killer Sudoku — dashed cages with sums, no repeats inside a cage
• Classic Sudoku — the timeless 9×9 logic puzzle
• Thermo Sudoku — digits rise from the bulb along the thermometer
• Arrow Sudoku — the digits on an arrow add up to the circle
• Kropki Sudoku — white dot: consecutive; black dot: one is double
• Sandwich Sudoku — clues give the sum between the 1 and the 9
• Chess (anti-knight) Sudoku — no equal digits a knight's move apart
• Diagonal (Sudoku X) — both diagonals hold every digit once

★ Hints that teach
Tap Hint and CageDoku names the technique, highlights the cells and walks you through the reasoning step by step: unique cage combinations, the rule of 45, innies and outies, locked candidates, pairs, triples, X-Wing and more. Learn Killer Sudoku while you play.

★ Five honest difficulty levels
Gentle, Moderate, Tough, Diabolical, Extreme. A puzzle's level is the hardest human technique it needs — not a guess about how long it takes.

★ Daily 3 and streaks
Every day the same three puzzles for everyone: a Killer, a rotating variant and a quick 6×6 Micro puzzle. Build your streak and protect it with a streak freeze.

★ Beautiful and calm
Six themes, readable fonts, dark and light mode, big comfortable controls, pencil notes, auto-notes, undo/redo, drag to select several cells, vibration feedback.

★ Free to play, Pro if you want more
Free: Daily 3, daily hints, dark theme, puzzle generation.
Pro: unlimited hints and puzzles, statistics, the Weekly Variant Pack, streak freezes, all themes and fonts, PDF export.
Pro is available monthly, yearly (7-day free trial) or as a one-time lifetime purchase.

No account needed. Works offline. Your progress stays on your device.

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Recent changes:
First release of CageDoku: Killer Sudoku plus 7 variants (Thermo, Arrow, Kropki, Sandwich, Chess, Diagonal, Classic). No ads. Hints that explain the why. Daily 3 every day.