100% Free & Open Source

The Ultimate Sudoku
Experience

Intelligent puzzle generation, beautiful UI, powerful tools, and zero ads. The most advanced Sudoku app you'll ever need.

Smart Hints
Dark Mode
Unlimited Puzzles
Stats Tracking
Notes Mode
Ad-Free Forever
Fast & Lightweight
Community Driven
No Tracking
solve9.apk
S9
Solve9
Medium
Auto-solving...0%
1 mistake
Ad-free
Everything you need

Packed with Premium Features

Everything you need for the perfect Sudoku experience, completely free and without ads.

Core

Smart Puzzle Generation

Advanced backtracking algorithm creates unique puzzles with guaranteed single solutions.

4 Difficulty Levels

From Easy (40 clues) to Expert (24 clues), challenge yourself at your skill level.

Intelligent Hints

Get contextual help when stuck. Hints reveal correct values without ruining the fun.

AI

Auto-Complete

Smart detection fills obvious cells automatically when only one option remains.

Notes Mode

Add pencil marks with a 3×3 mini grid to track candidate numbers for each cell.

Mistake Tracking

Real-time error detection with visual feedback. Learn from your mistakes (max 3).

Game Statistics

Track your time, moves, mistakes, and complete game history of last 50 games.

Beautiful Dark Mode

Eye-friendly dark theme with smooth animations and custom color palettes.

Mobile-First Design

Touch-optimized interface with responsive layouts and intuitive controls.

Unlimited
Undo Actions
10
Saved Games
50
Game History

Powerful Game Tools

7 essential tools to enhance your gameplay and help you solve any puzzle.

Notes Mode

Add pencil marks to track candidate numbers

  • Toggle notes on/off for any cell
  • 3×3 mini grid for marking possibilities
  • Notes auto-clear when number is placed
  • Perfect for advanced solving techniques
Cell with pencil marks
1
2
4
6
7
9
Candidates: 1, 2, 4, 6, 7, 9

Track Your Progress

Comprehensive game statistics to monitor your improvement and celebrate achievements.

0
Games Tracked
0
Saved Games
0
Difficulty Levels
0+
Features

Sample Player Stats

Based on 50 games
Puzzle Completion Rate87%
Average Accuracy94%
Expert Level Solves31%
Fastest Solve (Easy)72%

Game Timer

Tracks elapsed time in HH:MM:SS format. Pauses when you pause the game. Stops automatically on completion.

Move Counter

Every cell placement is tracked. Review your efficiency and compare strategies across different games.

Complete History

Last 50 completed games stored with full stats: time, moves, mistakes, difficulty, and win/loss status.

Built with Love, Shared with the World

100% Open Source

Free forever. No ads. No tracking. No premium features locked behind paywalls. Just pure Sudoku enjoyment for everyone.

Open Code

Fully transparent source code on GitHub

MIT License

Use, modify, and distribute freely

Community

Built by developers, for everyone

No Ads

100% ad-free experience forever

Built With Modern Technology

Frontend

  • React Native & Expo
  • TypeScript
  • NativeWind (Tailwind CSS)

Features

  • Zustand State Management
  • Backtracking Algorithm
  • AsyncStorage Persistence

Star the repository • Report issues • Contribute code

Free forever · No account needed

Ready to Start Playing?

Download Solve9 now and experience the most intelligent, beautiful, and ad-free Sudoku game on mobile.

Version 1.6.0Latest
Free
Forever
No Ads
Ever
Open Source
Always