Features

Built for serious listeners

Every feature in Echo is built around one goal: turning any document, article, or URL into a narrator you can actually listen to for hours.

Kokoro Voice Engine, Customized for Listening

Echo is built on a Kokoro-based neural voice engine that runs entirely on your device — and what you hear is not the stock model. Getting an AI voice to survive an eight-hour novel is a different problem from getting it to read a sentence in a demo. We have spent months rebuilding the pipeline around long-form listening: pronunciation, prosody, pacing, emphasis, voice character, and playback continuity are all tuned independently and together. The specifics stay under the hood. The result is a narrator you can actually listen to for hours.

  • On-device synthesis
  • Tuned for long-form listening
  • Seamless chunk transitions
  • Holds up over hours

Reads Anything You Can Throw At It

Echo reads PDFs, EPUBs, DOCX and RTF, plain text, Markdown, and HTML. Paste a web URL and it fetches the page, extracts the main article, and reads only the content — headlines, navigation, comments, ads, and cookie banners stripped out. Share text or a link from any other app on your phone and Echo starts reading instantly. A built-in element blocker lets you tap any remaining junk on a rendered page to hide it, and remembers your picks per-domain, so each site gets cleaner every time you visit.

  • PDF, EPUB, DOCX, RTF
  • TXT, Markdown, HTML
  • URL article reader
  • Per-domain element blocker

Voice and Pronunciation Control

Real books are full of words a stock TTS engine stumbles on: fantasy names, foreign loanwords, Latin, technical jargon, medical vocabulary, regional spelling variants, and the long list of English words that change pronunciation depending on meaning. Echo ships with a deep pronunciation layer that handles them, plus context-sensitive logic refined against thousands of passages from real books. Anything it still gets wrong, you fix once in your personal dictionary and it stays fixed. Pick from the voice roster, blend your own in the voice mixer, or load a curated character or accent preset. Enunciation and pacing are exposed as real controls, not hidden defaults.

  • Voice mixer and presets
  • Personal pronunciation dictionary
  • Context-aware handling
  • Enunciation and pacing controls

And so much more

Every detail has been considered to deliver the best listening experience.

Full-Screen Reader with Word Highlighting

A large-type scrolling reader mode with word-level highlighting synced to the audio. Every word lights up at the instant it is spoken — read along, or just listen.

Bookmarks, Resume, and Chapters

Save any point in any book and jump back instantly. Echo also remembers your position automatically, and detects chapters in EPUBs, PDFs, and plain text for quick navigation.

Sleep Timer

Drift off to a book. Stop after a set duration or at the end of the current chapter — whichever feels right for the night.

Background Playback

Keep listening while you use other apps, exercise, cook, or commute. Audio continues seamlessly with the screen off and holds time accurately.

Community Library and Authors

Browse and submit shared audiobooks, read book detail pages with star ratings and reviews, follow author profiles, and see author updates and announcements in a social feed.

Free Public-Domain Books

Built-in search across Project Gutenberg and LibriVox gives you tens of thousands of classic titles, ready to listen to in a tap.

Offline Mode

Once the voice engine is loaded on your device, narration works without an internet connection. Perfect for flights, road trips, and remote areas.

Privacy Focused

Narration runs on your device. Your documents are never uploaded for read-aloud, and nothing leaves your phone unless you explicitly submit it to the community library.

Frequently asked questions

What can Echo read?

Echo reads PDF, EPUB, DOCX, RTF, plain text, Markdown, and HTML documents. It also reads web articles — paste any URL and it extracts just the main content. You can also share text or a link from any other app on your phone and it will start reading.

Is Echo free to use?

Yes. Echo is free to download and use, with a full-featured free tier. Premium options unlock the full voice roster and additional format support.

How does the AI voice technology work?

Echo is built on a Kokoro-based neural voice engine that runs entirely on your device. The engine has been extensively customized around long-form listening — pronunciation, prosody, pacing, and voice character are all tuned for real books rather than short demos.

Can I listen offline?

Yes. Once the voice engine is loaded on your device, narration works without an internet connection. Your saved books are always available offline.

Can I customize how words are pronounced?

Yes. Echo ships with a deep pronunciation layer that handles fantasy names, loanwords, technical jargon, and words whose meaning changes how they sound. If it ever gets a word wrong, you can add a fix to your personal pronunciation dictionary and it stays fixed for every book you read.

Can I customize the voice?

Yes. Pick from the full voice roster, blend two voices into a custom narrator with the voice mixer, or load a curated character or accent preset. Enunciation and pacing are exposed as real controls.

Is there a reader view?

Yes. A full-screen reader shows large scrolling text with word-level highlighting synced to the audio. Bookmarks, chapter navigation, and automatic resume are built in. A sleep timer lets you stop after a duration or at the end of a chapter.

Ready to start listening?

Download Echo for free and experience the future of audiobooks.

Download Echo