The Sudoku
You Deserve
Five difficulty levels. Daily challenges with streaks. Four premium themes. Smart puzzle scanning. An ad-free, distraction-free experience crafted with care — and it costs nothing.
What's Inside
Everything you need.
Nothing you don't.
Built for both beginners and seasoned solvers — Sudoku Universe strips away everything that doesn't make you a better puzzle player.
Zero Ads, Forever
No banners, no interstitials, no rewarded videos. The app is completely free and will always remain ad-free.
5 Difficulty Levels
From Easy warm-ups to Ultimate brain-busters — each level calibrated to challenge without frustrating.
Daily Challenges
A new puzzle every day, shared across all devices. Build streaks, earn achievements, and never miss a day.
Smart Puzzle Scan
Point your camera at any printed Sudoku and the app extracts and solves it — or lets you play it yourself.
Achievements
Unlock over 20 milestones for speed, accuracy, streaks, and exploration. Always something to aim for.
Auto-Save & Resume
Walk away mid-puzzle and come back exactly where you left off — including your notes and elapsed time.
Pencil Notes
Mark candidate numbers as notes while you think through a move. Tap again to remove them instantly.
Smart Hints
Stuck? Request a context-aware hint that reveals the next logical move — available per difficulty.
4 Premium Themes
Default, Midnight, Paper, and Ocean themes — each with curated color palettes and accent gradients.
Difficulty
Five levels.
One perfect fit.
Whether you're picking up Sudoku for the first time or chasing a sub-5-minute solve, there's a level built for today's mood.
Achievements
Always something to unlock
From your very first puzzle to a 30-day streak — every milestone is celebrated.
Speed Demon
Solve a Hard puzzle in under 5 minutes
Perfectionist
Complete a game with zero errors
Week Warrior
7 daily challenges in a row
Perfect Month
Every puzzle completed in a calendar month
Scanner
Scan and solve your first printed puzzle
Master Mind
Finish your first Master difficulty puzzle
Night Owl
Complete a puzzle after midnight
Monthly Master
30-day daily challenge streak
Themes
Play in your palette
Four handcrafted themes — swap between them any time, no restart needed.
FAQ
Questions, answered
Everything you might want to know before you tap install.
Is Sudoku Universe really free?
Completely. There are no ads, no banners, no rewarded videos, and no in-app purchases that gate features. Every puzzle, theme, and the Daily Challenge are free for everyone, forever. Donations are entirely optional and never unlock anything.
Does it work offline?
Yes — fully. Puzzles are generated on your device and the entire app runs without a network connection. There are no servers to reach, so you can solve on a flight, in the subway, or anywhere with no signal.
What data do you collect about me?
None. We don't use analytics, ad SDKs, or trackers, and we have no account system. Your game history, statistics, and achievements live only on your device. See our Privacy Policy for the full detail.
How does the Daily Challenge work?
Every day a new puzzle unlocks that is identical for every player worldwide, generated deterministically from the date. Solve it to extend your streak; the in-app calendar marks every day you've completed and tracks your current and longest runs.
Can I scan a printed Sudoku?
Yes. Point your camera at any newspaper or book puzzle and the smart-scan feature reads the grid on-device using offline text recognition. Review the detected numbers, fix anything if needed, then play or solve it. Camera frames are processed in memory and never stored or uploaded.
Which Android version do I need?
Sudoku Universe runs on Android 7.0 (Nougat) and newer, so it works on virtually every phone and tablet still in use today.
Will my progress sync across devices?
Today, all progress is stored locally for maximum privacy, and Android's built-in backup can carry it to a new device. Optional, privacy-respecting cloud sync is on our roadmap — and it will always be opt-in.
How do I report a bug or request a feature?
Use the contact options below — pick Technical Support, Bug Report, or General Query, and your message opens pre-formatted in your email app. We read every single one.
Get Started
Free today.
Free forever.
No account, no paywall, no ads — not now, not ever. Install in seconds and your first daily streak starts today.
- Zero data collected
- Android 7.0+
- Works fully offline
Like what we're building?
Sudoku Universe is built by a tiny team in our spare time and given away for free. If it's brightened your commute or sharpened your mornings, a small one-time tip helps cover the costs of keeping it maintained, updated, and ad-free. It's entirely optional — every feature stays free either way.
Get in Touch
We're here to help
Choose the right category and we'll make sure your message reaches the right place.
Technical Support
App crashing, syncing issues, or something unexpected? Tell us exactly what happened.
General Query
Questions, feature suggestions, or just want to say hello? We read every message.
Report a Bug
Found something broken? Detailed bug reports help us ship fixes faster for everyone.