Read and listen in perfect sync.
Upload your EPUB and audiobook. We align the narration to the text and hand back one synced EPUB — the word lights up exactly as it’s spoken. Plays in Thorium and Colibrio today; Apple Books export is in beta.
Three steps from your files to a synced book
No accounts to wrangle, no formats to learn. Drop two files in and get one back.
Upload
Drop in your EPUB and audiobook. We accept M4B, MP3, and M4A, split across as many files as your book needs.
Align
We transcribe the narration, match it to the text, refine every timestamp, and score the sync quality before you pay.
Download
Get one synced EPUB with read-along audio, ready for Thorium and Colibrio today.
Sync your book
Upload an EPUB and audiobook to create a synced EPUB for any device.
Upload files
Drop your EPUB + audiobook, we align and package the synced EPUB.
Works across your readers
Bookwave outputs standards-based EPUB 3 with Media Overlays — the same read-along format modern readers use.
Thorium Reader
Excellent EPUB 3 support with Media Overlays on Windows, macOS, and Linux.
Colibrio
Lightweight reader with solid overlay playback, including on Android.
Apple Books
Export for iOS and macOS is in active beta while we finalize full playback parity.
Founding Member pricing
Paid-only syncs with a lifetime beta lock-in.
Lock in 50% off forever
Beta access only. When we launch publicly, pricing returns to $7.50. Beta users keep $3.75 for life.
- One-time payment per book
- First 10 hours included
- $0.38 per extra hour after 10
- Synced EPUB with read-along audio