Open-source Castbox alternatives

Audiobookshelf is a self-hosted server for audiobooks and podcasts. You point it at folders of audio files on your own hardware, and it serves them to a web player and companion mobile apps, so your collection stays on machines you control.

The server streams all audio formats on the fly, keeps listening progress per user and syncs it across devices, and supports multiple users with custom permissions. It can search for podcasts and auto-download new episodes, fetch metadata and cover art from several sources, edit chapters, merge files into a single m4b and embed metadata into audio files. Basic ebook support covers EPUB, PDF, CBR and CBZ, and ebooks can be sent to a device such as a Kindle.

Audiobookshelf is released under the GPL-3.0 licence and is fully open source, including the Android app and the iOS app, which are both in beta. A Progressive Web App, Chromecast support, automated daily backups and open RSS feeds are also available. Folder structure and naming affect how the library is detected, so the documentation on organizing media is worth reading first.

AntennaPod is the official repository of an open-source podcast manager for Android. It is described by its maintainers as easy to use and flexible, and it is meant for listeners who want to follow podcasts from an app that is community-developed and free of proprietary services.

The project is written in Java and licensed under GPL-3.0. Its community is organized around a forum for discussions about the app and podcasting in general, a bug tracker for reports and feature requests, and regular community calls. A beta testing program lets volunteers try new releases across many phone models and Android versions, which helps catch problems before a stable version ships.

Translations are managed through Weblate, and the app can be built like any other Android project. Repository topics reference the Podcasting 2.0 initiative. Because it is an Android application rather than a server product, it is installed on a phone or tablet and does not require running your own infrastructure.