MP4 to MP3 Converter | Flutter Mobile App

MP4 to MP3 Converter — Flutter App (Android & iOS)

A complete, ready-to-publish Flutter source code that lets users pick any video from their phone and instantly convert it to a high-quality MP3 audio file — 100% offline, no internet required, no subscriptions.

Powered by FFmpeg, designed with Material 3, and built with clean Riverpod architecture. Just change the package name, add your keystore, and ship to the Play Store or App Store.

Who Is This For?

• Developers who want to launch an audio utility app fast without building from scratch
• Freelancers looking for a solid, well-structured Flutter codebase to reskin
• Studios wanting a privacy-first, offline app with zero server costs

✅ Key Features

Core Conversion

• Convert any MP4 (or any video) to MP3 — powered by FFmpeg Kit
• Selectable bitrates: 96 kbps, 128 kbps, 192 kbps, 256 kbps, 320 kbps
• Real-time conversion progress bar with live percentage
• Cancel conversion at any time mid-process
• Detects and alerts if the selected video has no audio stream

Smart File Management

• Save to custom folder — user picks via Android Storage Access Framework
• Fallback to Downloads folder if no custom folder is set
• Automatic duplicate file handling (e.g. “song (1).mp3”, “song (2).mp3”)
• Persistent folder permission across app restarts

Conversion History

• Every converted file is automatically saved to a history list
• Shows file name, duration, bitrate, file size and conversion date
• Play converted MP3 directly in the app with a built-in audio player
• Share or open files with any external app (music players, cloud storage, etc.)
• Delete individual records or clear all history with one tap

⚙️ Settings & Customization

• Change default save location from the Settings tab
• Reset save location to the default Downloads folder
• Toggle Dark / Light mode — manual override from the AppBar
• Single seed color in main.dart controls the full Material 3 theme

Design & Architecture

• Material 3 design system with adaptive dark and light themes
• State management with Flutter Riverpod 2.x
• Clean separation: screens/, services/, widgets/, providers/, models/
• History persisted locally using SharedPreferences
• No external backend, no API keys, no Firebase required

What Is Included

• ✅ Full Flutter source code (Android + iOS)
• ✅ Native Android Kotlin code (MainActivity.kt) for file saving
• ✅ Custom folder picker using Android Storage Access Framework
• ✅ Complete documentation.html with step-by-step setup guide
• ✅ key.properties.example template for Android signing
• ✅ App icon asset (1024×1024 PNG) ready for flutter_launcher_icons
• ✅ .gitignore pre-configured to exclude keystore and signing files
• ✅ flutter analyze passes with zero issues

️ Technical Specifications

• Framework: Flutter 3.x / Dart 3.x
• State Management: Flutter Riverpod 2.6
• Audio Engine: ffmpeg_kit_flutter_new_audio 2.5
• Android min SDK: 24 (Android 7.0 Nougat and above)
• Android compileSdk: 36
• iOS minimum target: iOS 14 and above
• Package name: com.smallburnstudios.mp4tomp3 (fully customizable)
• Design system: Material You / Material 3

Documentation Covers

1. Introduction & feature overview
2. System requirements (Flutter SDK, Android Studio, Xcode, JDK 17)
3. Folder structure map
4. How to change the package name / Application ID
5. How to change the app name (Android + iOS)
6. How to change the app icon (with flutter_launcher_icons)
7. How to change the app theme color (single line change)
8. Android — Generate a release keystore
9. Android — Create key.properties
10. Android — Update build.gradle.kts with release signing
11. Build release APK / AAB
12. iOS — Change Bundle ID
13. iOS — Signing & Provisioning Profiles
14. Troubleshooting common errors
15. Changelog (starting v1.0)
16. Support contact

Easy to Customize

• Change app color: One line in lib/main.dart
• Change package name: Two fields in build.gradle.kts + rename Kotlin folder
• Change app name: One line in AndroidManifest.xml + one line in Info.plist
• Change app icon: Replace assets/icon/icon.png and run one command

Privacy & Security

• Fully offline — no internet permission required
• No analytics, no crash reporting, no user tracking
• No ads, no third-party SDKs that collect data
• All conversions happen entirely on the user’s device
• Keystore and signing credentials are excluded from Git by default

Changelog

v1.0.0 — August 2026 (Initial Release)

• First release of MP4 to MP3 Converter
• FFmpeg-powered audio extraction from any MP4 video file
• Custom output folder selection using Android Storage Access Framework
• Full conversion history screen with file details and quick actions
• Share and open converted MP3 files directly from the app
• Material 3 design with dark and light theme support
• About dialog with app information and feature list
• Supports Android 7.0 and above (API level 24+)
• Supports iOS 14 and above

Support

We aim to reply within 24 to 48 hours. Use the Comments section on the item page, or email us directly. Please include your purchase code in your message.

© 2026 TechArt Studios · MP4 to MP3 Converter