Listen (TTS)
Readest can read any book out loud. TTS works on every platform, with an option to choose between on-device voices and higher-quality cloud voices. Playback continues in the background with lock-screen controls.
Start TTS
In the reader, press T or tap the speaker icon in the top toolbar. Playback starts from the current paragraph and continues through the chapter.
Playback controls:
| Action | Shortcut |
|---|---|
| Play / Pause | Space |
| Next sentence | Ctrl+] / Cmd+] |
| Previous sentence | Ctrl+[ / Cmd+[ |
| Next paragraph | Ctrl+Shift+} / Cmd+Shift+} |
| Previous paragraph | Ctrl+Shift+{ / Cmd+Shift+{ |
You can also read aloud a selection only — select text in the reader and press Ctrl+R / Cmd+R. Readest reads the selection and stops.
Lock-screen controls and system media keys work on iOS, Android, macOS, and Windows — pause and skip without opening the app.
TTS engines
Readest ships three engines.
- Native (system) TTS — uses the operating system's built-in voices. Fully offline, instant response, works on Android platform.
- Web Speech API — browser-based TTS when running in the web app. Depends on what the browser exposes.
- Edge TTS — cloud-synthesized neural voices from Microsoft Edge's TTS. High quality, natural-sounding, many languages. Requires a network connection and sends the current sentence to Microsoft's servers for synthesis.
If you'd rather keep everything on-device, stick with Native TTS.
Voices & languages
Every engine exposes its own list of voices, filtered by the language of the current book. Readest automatically switches voices when a book contains multiple languages, so a bilingual edition uses the right voice for each passage.
To add more voices:
- macOS — Currently not supported.
- Windows — Currently not supported.
- Android — system TTS settings, installed engines (Google TTS, Samsung TTS, etc.).
- iOS — Currently not supported.
Newly installed voices show up in Readest the next time you open the voice picker.
Speed & controls
- Speed — 0.5× to 3×, in fine increments. The default is 1×.
- Sleep timer — optional auto-stop after a set duration.
Speed changes take effect immediately — mid-sentence if needed.
Sentence highlighting
While TTS plays, the current sentence is highlighted in the book. Settings under TTS → Highlighting let you tune:
- Style — highlight, underline, squiggly or outline.
- Color — the highlight color.
In paginated mode, Readest auto-advances the page when the reader crosses the edge of the visible content. In scrolled mode, the view scrolls smoothly to keep the currently-spoken sentence in view.
For pronunciation fixes (e.g., making TTS read "LLM" correctly), see Proofread rules — rules can be scoped to TTS-only so they don't touch the visible book text.