How it works
Listenbound turns a book into a narrated audiobook without sending it anywhere.
Your browser reads the book
EPUB and text files are opened on your device. Chapters, paragraphs, and sentences are found in the file's own structure.
The voice loads once
The narration voice is Kokoro-82M, an open-source model released under the Apache-2.0 license. Your browser downloads it from Hugging Face the first time and keeps it cached.
Narration runs ahead of you
Each sentence is spoken on your device, using your graphics hardware when available. Long sentences are split at natural pauses so nothing gets cut off, and silences are evened out so the voice flows naturally.
You listen and follow along
Sentences play back to back with no gaps. The text highlights as it's read, and you can jump to any chapter or sentence.
Privacy
Books you open stay on your device: the text is never uploaded, stored on a server, or shared. The only outside request is the one-time download of the voice model.
Supported files and limits
- DRM-free EPUB (.epub) and plain text (.txt). Books bought with DRM can't be opened.
- English narration. Other languages may be read with an English accent.
- Narration is fastest on computers with a modern graphics chip; on others it may pause to catch up.