Open Sudoku: No Ads & Offline

Play classic Sudoku with no ads, no subscriptions, and no paywalls. Open Sudoku is a fast, private logic puzzle for iPhone and iPad that works fully offline—and every puzzle, hint, and feature is free. PURE SUDOKU, COMPLETELY FREE • No banner, video, interstitial, or pop-up ads • No subscriptions, paid hints, lives, currencies, or locked puzzles • Tips support development but unlock nothing • Start instantly with 600 validated puzzles stored on your device SIX LEVELS FOR EVERY SOLVER • Beginner: start with naked singles and a friendlier board • Easy: build confidence with single-candidate techniques • Medium: practice pairs and pointing patterns • Hard: work through subsets and intersections • Expert: take on complex combinations and deeper deductions • Master: face the catalog's maximum challenge • Get 100 unique 9x9 puzzles at every level • Choose any difficulty immediately—there is no forced path, daily streak, or trophy grind PLAY YOUR WAY • Six skill levels, from Beginner to Master • Cell-first or digit-first input • Pencil notes, automatic candidates, and note cleanup • Unlimited undo and redo • Optional mistake checking with immediate visual feedback • Remaining-number counts and clear conflict highlighting • Pause and resume with progress saved automatically • Share a puzzle link and clean image with friends LEARN THE LOGIC • Progressive hints point to an area, explain singles when available, then reveal a correct number only if you ask • Study naked and hidden singles, locked candidates, pairs, X-Wing, XY-Wing, Swordfish, coloring, and logical chains • Open the built-in Learn guide for plain-language explanations of what to look for and why each technique works • Every included puzzle is validated to have exactly one solution MADE FOR IPHONE AND IPAD • Native, responsive controls • Dedicated iPad sidebar and landscape layout • Hardware keyboard shortcuts • Light, dark, high-contrast, and large-digit options • Accessible board actions and readable notes PLAY SUDOKU WITH FRIENDS • Start a private online Sudoku race at any level and challenge a friend to solve the same grid live • Play multiplayer Sudoku by invite link or send the challenge directly to a friend • Make one ranked attempt on any included puzzle and compare verified completion times • Open Puzzle Leaderboard after finishing to see the Top 3 and your own place • Open Overall Leaderboard in Progress to compare ranked players or filter it to friends • Add friends by exact generated player name • Send any completed Sudoku as a private time-to-beat challenge; your friend gets the same grid • Every guest receives a generated, profanity-safe player name • No chat, biographies, or public player directory PRIVATE, OFFLINE, AND IN YOUR CONTROL • Play without an account or internet connection • History and progress stay on your device by default • Sign in with Apple backs up your progress and player profile across devices • Puzzle pack updates are downloaded in the background and kept for offline play • No advertising tracking HOW TO PLAY CLASSIC SUDOKU Fill the 9x9 grid so every row, column, and 3x3 box contains the numbers 1 through 9 exactly once. Every included Sudoku has one valid solution. Use logic, pencil notes, and candidate elimination to solve the grid; no arithmetic is required. FOR BEGINNERS, EXPERTS, ADULTS, AND SENIORS New players can learn Sudoku step by step with Beginner puzzles and progressive hints. Experienced solvers can jump directly to Hard, Expert, or Master grids. Large digits, high contrast, flexible input, and native iPad layouts keep the number puzzle clear and comfortable at any skill level. Whether you want a relaxing beginner puzzle, a quick brain-training break, or a challenging Master grid, Open Sudoku keeps the experience calm, readable, and focused on logic. Stay solo offline or go online only when you want a private Sudoku challenge with friends—always without ads, paywalls, or locked hints.