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🧩 Sudoku Generator

Local Sudoku generator and game with real 5-level technique-based difficulty (Easy/Medium/Hard/Expert/Evil), triple highlighting (row-col-box/same-number/selected), auto-pencil candidates, 4-stage progressive hints, local best times, daily puzzle, URL sharing, 200-step undo/redo, dark mode. Mobile-friendly 44px touch targets. No login, default no ad scripts, no upload, default no third-party analytics.

Local · No upload · No login · Default no ad scripts · Default no third-party analytics

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Local Sudoku generator and game. Real 5-level technique-based difficulty (Easy/Medium/Hard/Expert/Evil) fixes the "fake difficulty labelling" that plagues mainstream Sudoku apps. Triple toggle-able highlighting (row-col-box / same-number / selected cell) matches the NYT Sudoku 2025 upgrade. Auto-pencil candidate updates, 4-stage progressive hints (region pulse → technique name → target cell → answer digit), 200-step undo/redo, local best times per difficulty, daily puzzle (date-seeded deterministic), URL hash puzzle sharing (fail-closed validator), PNG board export, prefers-color-scheme dark mode. Mobile-friendly 44px touch keypad (WCAG 2.5.5), iOS soft-keyboard never hides the board. Zero login, default no ad scripts, zero upload, default no third-party analytics — game data is not uploaded by the tool. Full keyboard support: digits 1-9 to fill, Shift+digit for notes, arrow keys to navigate, Ctrl+Z/Y for undo/redo, H for hint, P to pause.