Questions about Tandem? We're here to help.
Email us at support@tandembooks.co. We aim to respond within 2 business days.
Tandem is an app for switching between an ebook and its audiobook without losing your place. Import a DRM-free EPUB, pair it with a matching M4B or MP3, and move between reading and listening in one app.
Tandem reads EPUB ebook files and plays M4B or MP3 audiobooks. Import your files using the + menu in the library.
Import both files. Tandem will try to match them when the title and author look right, or you can pair them manually from the book's menu.
When you switch modes, Tandem uses a short audio check to place you in the matching part of the book, then keeps the ebook and audiobook aligned as you continue. The first handoff in a chapter can take a few seconds, and later switches in the same area are faster because Tandem remembers that position on your device.
On iOS, this permission allows Tandem to optionally use Apple's on-device transcription for sync instead of the cloud service. Your microphone is never recorded.
Reading and listening work offline. Finding your place during a fresh ebook-to-audiobook handoff can require a short internet request to analyze a small piece of audio. Once Tandem has matched that area, it remembers the result on your device.
iOS 26, iPadOS 26, and macOS 26. It's a universal app — buy once, use on all three.
Email support@tandembooks.co with details. For bugs, please include what you were doing and which book you were reading.
See our privacy policy for details on what data Tandem stores and how it's used.