u/Funmaker1893

Hey everyone,

I'm building a Flutter-based mobile app and looking for the best local, on-device TTS solution that works well on both Android and iOS. The use case is reading out AI-generated text to users — ideally with decent voice quality, low latency, and no cloud dependency.

Here's what I've evaluated so far:

Native options:

• flutter_tts (wraps Android TTS / AVSpeechSynthesizer on iOS) — works offline, but voice quality varies a lot by device. No onRangeStart word-boundary callbacks on many Android OEM engines (Samsung, Pico), which kills word highlighting features.

Models I'm considering:

• Kokoro — surprisingly good quality for its size, Apache 2.0, seems very popular lately
• Coqui TTS (XTTS v2) — great quality but heavy, might be too much for mobile
• Piper TTS — lightweight, fast, decent quality, used in Home Assistant
• StyleTTS 2 — impressive demos but integration complexity?
• MeloTTS — fast, multilingual, MIT license

My constraints:

• Must run fully on-device (privacy-first app, no cloud calls)
• Target: Android 12+ with 6 GB RAM minimum
• Need word boundary callbacks for karaoke-style word highlighting
• German + English language support required
• Reasonable model size (ideally under 200 MB)
• Flutter integration preferred, but native Android/iOS bridge is fine

My questions for the community:

1. Which model gives the best quality/size tradeoff for mobile in 2026?
2. Anyone running Kokoro or Piper on Android successfully with Flutter?
3. Is word-level timing/boundary data available from any of these without a full forced-alignment pipeline?
4. Any experience with Sherpa-ONNX as a TTS runtime on mobile?

Would love to hear what setups you're actually running in production vs. just tinkering with. Benchmarks, APK size impact, cold-start latency — any real-world numbers appreciated!

Thanks

Hey everyone,

I'm building a Flutter-based mobile app and looking for the best local, on-device TTS solution that works well on both Android and iOS. The use case is reading out AI-generated text to users — ideally with decent voice quality, low latency, and no cloud dependency.

Here's what I've evaluated so far:

Native options:

• flutter_tts (wraps Android TTS / AVSpeechSynthesizer on iOS) — works offline, but voice quality varies a lot by device. No onRangeStart word-boundary callbacks on many Android OEM engines (Samsung, Pico), which kills word highlighting features.

Models I'm considering:

• Kokoro — surprisingly good quality for its size, Apache 2.0, seems very popular lately
• Coqui TTS (XTTS v2) — great quality but heavy, might be too much for mobile
• Piper TTS — lightweight, fast, decent quality, used in Home Assistant
• StyleTTS 2 — impressive demos but integration complexity?
• MeloTTS — fast, multilingual, MIT license

My constraints:

• Must run fully on-device (privacy-first app, no cloud calls)
• Target: Android 12+ with 6 GB RAM minimum
• Need word boundary callbacks for karaoke-style word highlighting
• German + English language support required
• Reasonable model size (ideally under 200 MB)
• Flutter integration preferred, but native Android/iOS bridge is fine

My questions for the community:

1. Which model gives the best quality/size tradeoff for mobile in 2026?
2. Anyone running Kokoro or Piper on Android successfully with Flutter?
3. Is word-level timing/boundary data available from any of these without a full forced-alignment pipeline?
4. Any experience with Sherpa-ONNX as a TTS runtime on mobile?

Would love to hear what setups you're actually running in production vs. just tinkering with. Benchmarks, APK size impact, cold-start latency — any real-world numbers appreciated!

Thanks

Hey everyone,

I'm building a Flutter-based mobile app and looking for the best local, on-device TTS solution that works well on both Android and iOS. The use case is reading out AI-generated text to users — ideally with decent voice quality, low latency, and no cloud dependency.

Here's what I've evaluated so far:

Native options:

• flutter_tts (wraps Android TTS / AVSpeechSynthesizer on iOS) — works offline, but voice quality varies a lot by device. No onRangeStart word-boundary callbacks on many Android OEM engines (Samsung, Pico), which kills word highlighting features.

Models I'm considering:

• Kokoro — surprisingly good quality for its size, Apache 2.0, seems very popular lately
• Coqui TTS (XTTS v2) — great quality but heavy, might be too much for mobile
• Piper TTS — lightweight, fast, decent quality, used in Home Assistant
• StyleTTS 2 — impressive demos but integration complexity?
• MeloTTS — fast, multilingual, MIT license

My constraints:

• Must run fully on-device (privacy-first app, no cloud calls)
• Target: Android 12+ with 6 GB RAM minimum
• Need word boundary callbacks for karaoke-style word highlighting
• German + English language support required
• Reasonable model size (ideally under 200 MB)
• Flutter integration preferred, but native Android/iOS bridge is fine

My questions for the community:

1. Which model gives the best quality/size tradeoff for mobile in 2026?
2. Anyone running Kokoro or Piper on Android successfully with Flutter?
3. Is word-level timing/boundary data available from any of these without a full forced-alignment pipeline?
4. Any experience with Sherpa-ONNX as a TTS runtime on mobile?

Would love to hear what setups you're actually running in production vs. just tinkering with. Benchmarks, APK size impact, cold-start latency — any real-world numbers appreciated!

Thanks