M4B to MP3 Converter

M4B to MP3 Converter is the ultimate audiobook conversion tool for Android. Whether you have a library of M4B files from Audible, iTunes, or any other source, this app converts them into universally compatible formats so you can listen on any device or player — no internet required, no uploads, 100% on-device.

🎧 Supported Formats
Input: M4B · M4A · WAV Output: MP3 · AAC · OGG Vorbis · FLAC

✨ Key Features
Batch Conversion Add multiple files at once and convert them all in one go. A live progress card keeps you informed with file-by-file and overall progress.

Chapter Splitting Automatically detect and split M4B chapters into individual tracks — perfect for audiobooks with dozens of chapters.

Metadata & Cover Art Preserve or edit title, artist, album, and year tags. Embed custom cover art directly into the output files.

High-Quality Audio Choose a fixed bitrate (64 kbps – 320 kbps) or enable VBR (Variable Bit Rate) for the best quality-to-size ratio. Quality presets let you save your favourite settings.

Background Processing Conversions run in a foreground service — you can switch apps, lock your screen, or take a call without interrupting the conversion.

Conversion History Every completed conversion is saved to a searchable history log. Tap any entry to re-open the output folder instantly.

Sleep Timer Set a countdown timer to automatically pause conversion after a set time — great for overnight batch jobs.

Home Screen Widget Monitor active conversion progress right from your home screen without opening the app.

Output Folder Control Choose exactly where your converted files land using Android's Storage Access Framework. Full SAF support, including external SD cards.

Quality Presets Create and save named presets (e.g. "High Quality MP3", "Small Podcast OGG") for one-tap configuration.

Material You Design Clean, modern Material Design 3 UI with dynamic colour theming. Supports light mode, dark mode, and system default.

🔒 Privacy First
All conversion work happens entirely on your device. No audio files, metadata, or personal data are ever uploaded to any server.

💎 Premium (Remove Ads)
Upgrade once to remove all advertisements permanently and enjoy an uninterrupted, ad-free experience. One-time in-app purchase — no subscription.

📋 Permissions Explained
Storage / Media access – to read your audio files and save converted output.
Foreground service – to keep conversions running reliably in the background.
Notifications – to display real-time conversion progress.
Internet – used only for advertisements in the free version.