TTS models
Inworld provides a family of state-of-the-art TTS models, optimized for different use cases, quality levels, and performance requirements.
Realtime TTS-2
Our flagship, top-ranked model — the best choice for production
- Best quality and steerability, with natural language steering for more contextually aware speech
- Support for 200+ languages and locales
- Ultra-low latency (100 ms TTFB*) at high concurrency
- High quality instant voice cloning
- Enhanced timestamps with phonetic details and visemes
* P90 time to first audio byte, measured server-side — excludes network latency.
Models overview
| Name | Model ID | Description | Supported languages |
|---|---|---|---|
| Realtime TTS-2 | inworld-tts-2 | Our most powerful model with natural language steering and the strongest multilingual capabilities — the best choice for production quality | 200+ languages and locales — see Languages |
| Realtime TTS-2 Flash | inworld-tts-2-flash | Our fastest, most cost-efficient model — significantly lower latency than inworld-tts-2, ideal for real-time agents and high-volume workloads | 200+ languages and locales — see Languages |
Using an earlier model? Previous-generation models (inworld-tts-1, inworld-tts-1-max, inworld-tts-1.5-max, inworld-tts-1.5-mini) are deprecated and not recommended for new projects. inworld-tts-1 and inworld-tts-1-max were discontinued on June 15, 2026 and requests to them are automatically routed to newer models. If you're still using any of these, we recommend migrating to the TTS-2 family for better quality, latency, and cost.
Feature comparison
| Feature | Realtime TTS-2 | Realtime TTS-2 Flash |
|---|---|---|
| Best for | Production workloads that need the best quality and steerability | Latency-critical, high-volume, and cost-sensitive workloads |
| Quality | Top-ranked flagship — best quality and steerability | High quality at the lowest latency and cost |
| Latency (TTFB) * | 100 ms | 20 ms |
| Instant voice cloning | ||
| Professional voice cloning Beta | ||
| Inline pronunciation | ||
| Multilingual | 200+ languages | 200+ languages |
| Steering | ||
| Pause controls | ||
| Timestamp alignment | ||
| Zero data retention |
* P90 time to first audio byte, measured server-side — excludes network latency.