Why Yomite's Speech Synthesis Runs Entirely On-Device
Yomite never sends your text to the cloud. Here's exactly what runs on-device — speech synthesis, article extraction, and the Aozora Bunko reader — and why.
Yomite’s marketing pages repeat the same phrase — “fully offline,” “on-device processing.” That’s not just a tagline, it’s a design constraint. Here’s exactly what runs on-device, and why.
Speech synthesis itself runs on-device
After the initial voice download, Yomite’s speech synthesis works without an internet connection. Unlike the typical cloud TTS setup — send text to an API, get audio back — synthesis runs entirely on Apple Silicon (A12 Bionic or later iPhone/iPad, M1 or later Mac).
That means the same quality on airplane mode, underground, or anywhere without signal. Since there’s no per-request server round-trip, playback quality never depends on your connection.
Your text never leaves the device
Content you load into Yomite — EPUB, TXT, PDF, or a web article — never passes through our servers.
- EPUB / TXT import: files are pulled in from your device by your own action, no server involved
- Web Reader: the URL you paste is fetched in an on-device WebView, and article extraction happens locally
- Aozora Bunko reader: works displays and reads on-device
Reading content and playback history are never transmitted to our servers either. As stated in our privacy policy, speech synthesis and text processing are designed to complete entirely on the user’s device.
No data sent to third-party AI services
Yomite doesn’t send your text or reading data to external AI services like OpenAI, Google AI, Anthropic, or Azure. Inference — including the speech synthesis engine — happens entirely on-device. This also aligns with Apple App Store Review Guideline 5.1.2(i), which governs third-party transmission of user data.
There are no connections to ad networks or tracking telemetry servers. We use GA4 for analytics, but it’s wired through Consent Mode v2 and doesn’t collect data without consent.
No account, by design
Yomite has no login and no account registration. App Store purchase transactions (signed receipts) are verified on-device and are never sent to our servers. The app is designed without any information that uniquely identifies a user.
Deleting your data is simple: delete the app, or clear its data from OS settings. There’s no “account deletion request” flow to go through.
Why we built it this way
Two reasons, mainly.
- Privacy — what you’re reading can reveal a lot about your interests, beliefs, and habits. If there’s no need to hand that to an external server, we’d rather not.
- Availability — an app that doesn’t depend on the cloud isn’t affected by outages or a service shutting down. Download a voice once, and the experience stays the same indefinitely.
On-device processing has trade-offs — on-device models are more constrained than large cloud models. We think that trade-off is worth it.
The short version
When we say Yomite “runs offline,” that’s not just about speech synthesis. Text import, article extraction, the Aozora Bunko reader, purchase verification — nearly everything happens on-device.
Full details are in our Privacy Policy. Questions? Reach us at [email protected].
— Yomite Team