About Sudoku Dark

Free, dark-themed Sudoku for everyone

Our Mission

Sudoku is one of the most played logic puzzles in the world, yet most digital versions feel like afterthoughts — cluttered interfaces, aggressive monetisation, and white backgrounds that hurt your eyes after ten minutes. We built Sudoku Dark to fix that.

Our goal is simple: give every player a fast, clean, distraction-free Sudoku experience that respects their intelligence, their privacy, and their eyes. No dark patterns, no paywalls hiding core features, no nagging to rate the app. Just puzzles.

The Game

Sudoku Dark offers classic 9×9 Sudoku puzzles in a carefully designed dark interface built for comfortable, distraction-free play. Whether you are a beginner working through your first puzzle or an expert chasing your fastest Expert-difficulty time, the app has everything you need.

• Four difficulty levels: Easy, Medium, Hard, and Expert — each graded by the logical techniques required, not just the number of given clues
• Daily puzzle challenges with a global leaderboard — the same puzzle for every player, every day
• 88 achievements covering speed records, streaks, difficulty mastery, and more
• Statistics tracking — games played, win rate, best times, and daily streak history
• Note-taking (pencil marks) with automatic conflict clearing when a number is placed
• Undo and hints — step back any move, or reveal a single cell to break through a block
• Offline-first — all puzzles and features work without an internet connection
• Optional sign-in for cross-device sync, leaderboards, and social features via Google or Apple

The web version is a Progressive Web App (PWA) — install it from your browser and play offline, just like a native app. On mobile, Sudoku Dark is available on the Google Play Store and the Apple App Store.

Our Values

Three principles guide every decision we make about the product:

• Privacy first. In guest mode, no data ever leaves your device. If you sign in, we collect only what is needed to make cross-device sync and leaderboards work — nothing more. We do not use analytics trackers, crash-reporting SDKs, or social media pixels. We never sell your data.
• Offline first. An internet connection should be optional, not required. Puzzles are generated on-device. Your stats and achievements are stored locally. The app opens in under a second regardless of your network situation.
• Free, genuinely. All four difficulty levels, the daily challenge, all 88 achievements, and the full leaderboard are free with no gating. We sustain the project through optional ads, not by locking features behind a subscription.

The Developer

Sudoku Dark is developed by Carlos Codes for Me GmbH, a software company focused on building high-quality, privacy-respecting applications. The project started as a personal tool — a Sudoku app with a proper dark theme for late-night play — and grew into a full-featured product after early users asked for leaderboards, achievements, and daily challenges.

The app is built with Flutter, allowing a single codebase to deliver a consistent experience across Android, iOS, and the web. The backend uses Appwrite for authentication and cloud sync, chosen for its open-source nature and strong privacy defaults.

Website: carloscodesfor.me

What's Next

Sudoku Dark is actively developed. Upcoming work includes expanded social features, tournament modes, and additional game variants for players who want something beyond classic 9×9 Sudoku. If you have a feature request or idea, we'd love to hear it — reach out via the contact page.

Contact

For support, feedback, privacy requests, or any other questions:

Email: support@carloscodesfor.me

We aim to respond to all enquiries within 48 hours. For data deletion requests, use the self-service form on the Privacy Policy page for an instant response.

Legal

Use of Sudoku Dark is subject to our Terms of Service and Privacy Policy.