Cloud text-to-speech is easy: upload a file, wait a moment, press play. That convenience has a cost you only notice when the document is something you would not paste into a random chat box — a draft, a medical PDF, internal research, or personal notes.
On-device TTS flips the default. The model runs where the document already is. Nothing sensitive has to leave the machine for narration to work.
Cloud readers: the tradeoff
Typical cloud readers shine at:
- Huge voice libraries and many languages
- OCR on scanned pages
- Sync across phone, tablet, and desktop
They usually require:
- An account
- Uploading or syncing the file
- Trust that the provider’s retention and training policies match yours
For a public blog post, that tradeoff is fine. For a confidential PDF, it is not.
What “on-device” means in Junco Reader
Junco Reader narrates PDFs, Markdown, TXT, and pasted text with Kokoro inside the browser. Parsing and synthesis happen locally. You can download the voice model once; after that, revisits use the browser cache.
There is no Junco Reader account and no document upload to Junco servers. Anonymous page analytics may record that someone used the tool — not what they listened to.
On-device on iPhone for newsletters
The Junco iOS app takes a different ingest path — your inbox — then can narrate with on-device premium voices as well. That is the right shape when the problem is “thirty newsletters every morning,” not “this one PDF right now.”
| Junco Reader (browser) | Junco iOS | |
|---|---|---|
| Best for | One-off PDFs and pasted text | Daily newsletter podcast |
| Account | None | Yes |
| Docs leave device for TTS? | No | Narration can run on-device |
| Price to try | Free | Free on the App Store |
Choosing without the hype
Pick a cloud reader if you need OCR, dozens of languages, or a polished multi-device library and you are comfortable uploading the material.
Pick Junco Reader if you want a free, private listen of a document you already have, without creating an account.
Pick Junco on iPhone if the pile is recurring newsletters and you want them summarized into a short daily episode automatically.
Privacy is not a feature sticker. It is a decision about where the bytes go. On-device TTS makes “nowhere else” the default.