Mad Sudoku

Love Sudoku but ready for a bigger challenge? Mad Sudoku combines classic Sudoku rules with cage arithmetic — group cells by cages, each with a target number and math operation (+, −, ×, /). Use logic, not guesswork, to fill the grid. How It Works Place numbers 1–9 so every row, column, and box is unique — just like Sudoku. But each cage also has a math target you must satisfy. Start with easier puzzles that give you pre-filled cells, or go extreme with a completely blank grid. Four Difficulty Levels • Easy — 24 cells pre-filled, perfect for learning • Medium — 16 cells, a satisfying step up • Hard — 8 cells, for experienced players • Extreme — completely blank grid, pure logic Three Game Modes • Regular — full experience with timer, score, hints, and notes • Zen — no timer, no score, no mistake tracking — just you and the puzzle • Hardcore — no hints, no notes, no undo, one mistake and it's over Smart Features • Pencil notes to track candidates • Smart hint system that teaches, not just reveals • Undo up to 50 moves — even after game over • Auto-remove notes when you place a number • Highlight matching numbers across the grid Track Your Progress • Per-difficulty statistics: win rate, streaks, best and average times • Personal best indicators on completion • Score system with speed bonuses for fast moves Beautiful & Accessible • 4 themes: Light, Dark, High Contrast, and Monotone • Sound effects and haptic feedback • Accessibility labels for screen readers No account required. No internet needed to play. Your progress saves automatically.