Your books, perfectly in sync.

Voxlight supports M4B, MP3, M4A, AAC, FLAC, and WAV for audiobooks, and EPUB for ebooks. M4B is recommended for audiobooks as it preserves chapter markers in a single file — which is what most self-hosted setups produce. PDF and TXT support is planned for future releases.

Yes. If you can export or download your M4B and EPUB files from Audiobookshelf, you can import them into Voxlight. Save them to iCloud Drive or transfer via Files, and Voxlight takes it from there. Voxlight doesn't connect to Audiobookshelf directly (it's an on-device app, not a server client), but it works great with the files your library already has.

Voxlight listens to short samples from each chapter of your audiobook and matches them to the corresponding ebook chapters. Instead of processing the entire audiobook, it only needs small portions — making sync fast and lightweight. Everything runs on your device using Apple's Neural Engine.

Typically a few minutes per book. Voxlight only samples small portions of each chapter rather than processing the entire audiobook. For comparison, Storyteller takes 1-4 hours per book on server hardware. You can start reading and listening right away while the rest of your book syncs in the background.

No. All sync processing happens on-device using Apple's Neural Engine. Your audiobook files, ebook files, reading position, and listening data never leave your device. The only network features are optional iCloud sync (between your own devices, via Apple) and optional Readwise export (which you explicitly trigger). No analytics are collected without your consent. We have no interest in your data — we just want to build a good reader.

Absolutely. Voxlight is a fully featured audiobook player and EPUB reader independently. You can use it as a standalone audiobook player, a standalone ebook reader, or both together with sync. Many users may find value in the player or reader alone.

Voxlight requires iOS 17 or later (iPhone) or iPadOS 17 or later (iPad). CarPlay is supported for in-car listening. Apple Watch and visionOS support are planned for future releases.

You can sync up to 5 audiobook-ebook pairs for free, with no time limit. No credit card, no account, no trial that expires. This lets you fully test the sync quality with your own library before deciding to subscribe. The audio player and EPUB reader are completely unlimited on the free tier — sync is the only gated feature.

Honest answer: the sync engine is the core of Voxlight, and it requires ongoing work — improving alignment accuracy, supporting new formats, and optimizing performance across new hardware. At $29.99/year ($2.50/month), it's less than a single Audible credit. We considered a one-time purchase, but it doesn't sustain the kind of active development this feature needs. The free tier lets you verify the value before spending anything.

Voxlight works with DRM-free audiobook and ebook files. If you have DRM-free files in supported formats, they will work. Voxlight does not circumvent DRM protection. Many audiobook retailers (Libro.fm, Google Play Books, authors' direct sales) sell DRM-free files. If your library is in Calibre, you likely already have what you need.

Storyteller is an impressive open-source project that creates synced audiobooks, but it requires running a server (Docker), a command line, and 1-4 hours of processing per book. Voxlight does the sync on your iPhone in minutes with no server infrastructure. Storyteller gives you word-level precision; Voxlight gives you chapter-level sync on-device, with optional word-level via the Mac Processor companion app.

No. Voxlight works entirely on your iPhone with on-device sync processing. The Mac Processor is an optional companion app for power users who want word-level alignment precision — it runs Whisper locally on your Mac and exports the alignment data. Most users will get great results with the built-in on-device sync.

It's a companion app included with your Voxlight Pro subscription. It uses Whisper-based forced alignment running locally on your Mac to create word-level sync between your audiobook and ebook, then transfers the data to your iPhone. All processing stays on your hardware — nothing is uploaded.

After processing on your Mac, simply AirDrop the alignment file to your iPhone, or save it to iCloud Drive. Then import it in Voxlight's library under the book's sync settings.