Best Audiobook Player Apps for M4B and MP3 Files

You have audiobook files. M4B, MP3, maybe a mix. The files are already on your phone. What plays them?

If you want a fast answer:

• iPhone or iPad: BookPlayer. Free, open-source, reads M4B chapters, supports CarPlay and Apple Watch.
• Android: Smart Audiobook Player. Mature, feature-rich, handles M4B chapters and has the most playback options on Android.
• Android, free and open-source: Voice. No ads or purchase, reads M4B chapters, available on Google Play and F-Droid.

BookPlayer is the most capable local audiobook player on iOS. It reads M4B chapter marks and shows a chapter list, remembers where you left off, and supports variable speed from 0.5x to 3x. Library organization supports nested folders (Author > Series), so large collections stay manageable.

It is open-source (GitHub: TortugaPower/BookPlayer), free to use, and has an optional premium upgrade for cloud sync and some advanced features. The core playback features, including chapter navigation, bookmarks, and CarPlay, work without paying anything. The sleep timer can auto-restart when you tap your earbud, which is useful if you tend to set a timer and then want a few more minutes.

Imports audiobook files from the Files app, AirDrop, or direct download. Apple Watch playback is supported.

Bound is the simple one. You pay $4.99 once and get the whole app. No subscription or recurring payments hiding behind a premium tier.

It reads M4B chapters, supports bookmarks with notes, variable speed with pitch correction, and a sleep timer. CarPlay works. Bound can also stream files from cloud storage (Dropbox, OneDrive) and has smart rewind and custom seek intervals. Import local files through the Files app, AirDrop, or drag-and-drop in Finder.

Bound is single-developer software and the update pace has slowed compared to BookPlayer. It does what it does well, but it does less. There is no Apple Watch app or cloud sync. If you want a straightforward player with no recurring cost, Bound is a solid pick.

Smart Audiobook Player has been on Google Play since around 2013. It is the most feature-rich local audiobook player on Android, and it is not close.

M4B chapter support is full. Bookmarks include categories and notes. Speed control goes from 0.5x to 4x, which is wider than most. The sleep timer lets you shake the phone to add time without looking at the screen, which sounds minor until you are half-asleep and do not want to unlock your phone to extend the timer. Android Auto is supported. Progress is saved in local metadata files, so it survives app reinstalls.

The free version is a 30-day full trial, then reverts to a basic version. The paid unlock, around $2.50 one-time, adds bookmarks, equalizer, and cover art downloads. Without the unlock, you still get chapter navigation, speed control, and sleep timer.

The interface works but it looks like an Android app from 2016. If you care about visual polish, it is not the prettiest. If you care about playback features, it has everything.

Listen is the middle option on Android. It reads M4B chapters, supports bookmarks and speed control, and has a Material Design interface that looks more modern than Smart Audiobook Player. It also has pitch control, silence trimming, and automatic volume leveling, which few other local audiobook players offer.

The sleep timer and Android Auto support are there. Listen uses a library-based organization that relies on metadata rather than folder structure, which is cleaner if your files are tagged properly and messier if they are not.

$1.99 one-time purchase. Updates can be infrequent.

Voice is the free and open-source option. No ads, no in-app purchase, no tracking. Available on Google Play and F-Droid. If you want a local audiobook player that sends no data anywhere, this is it.

It reads M4B chapters, supports speed control, sleep timer, and Android Auto. Bookmarks are basic: it remembers where you stopped, but there is no categorized bookmark system with notes. Configurable auto-rewind brings you back a few seconds when you resume, which helps if you lose context between listening sessions.

The feature set is narrower than Smart Audiobook Player or Listen. No equalizer or cover art management. What it does, it does cleanly. If you want the simplest open-source player that handles M4B files, Voice is the one.

Developed by Paul Woitaschek (GitHub: PaulWoitaschek/Voice), originally called Material Audiobook Player.

Apple Music, Google Play Music, and most generic music players can open M4B and MP3 files. They will play the audio. The problem is they do not treat audiobooks like audiobooks.

They forget your position when you play something else. They do not show chapter lists or offer sleep timers. They put audiobook files next to music in the same queue. Switch between a podcast and an audiobook, and your music app will lose your place.

Dedicated audiobook players solve these problems. They remember where you paused, show chapter marks from the M4B file, and keep audiobooks separate from music. That is why they exist.

If your audiobook files are a pile of loose MP3s, most of these apps will play them, but you lose the ability to jump between chapters. Converting those MP3s into a single M4B with embedded chapters gives you chapter navigation in any of these players.

That is what Audiobook Converter does. Drag in your MP3 files, convert once, and the resulting M4B works in every app listed above with full chapter support. No installation, no account, browser-based.

• BookPlayer: bookplayer.app, GitHub, App Store
• Bound: boundapp.com, App Store
• Smart Audiobook Player: Google Play
• Listen Audiobook Player: Google Play
• Voice: GitHub, Google Play