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January 21, 2026

Inworld TTS 1.5

Launched Inworld TTS 1.5, our newest generation of realtime TTS models featuring:
  • Two New Models: Our flagship model inworld-tts-1.5-max is ideal for most use cases, with the best balance of quality and speed. For use cases where latency is the top priority, we also offer inworld-tts-1.5-mini.
  • Latency Improvements: Our new TTS-1.5 models achieve P90 latency for first audio chunk delivery under 250ms for our Max model and under 160ms for our Mini model, a 4x improvement compared to TTS-1.
  • More Expressive and More Stable: TTS 1.5 is 20% more expressive than prior generations and demonstrates a 25% reduction in word error rate.
  • Additional Languages: We’ve added support for additional languages, including Hindi, Arabic, and Hebrew, bringing total languages supported to 15.
August 22, 2025

Updates to Inworld TTS

Released an upgraded version of the Inworld TTS models with higher overall quality.
  • Speech Quality: Clearer, more natural speech with smoother pacing and more accurate pronunciation.
  • Voice Similarity: Cloned voices sound closer to the originals, preserving each voice’s unique style.
  • Non-English Languages: More consistent, reliable output across supported non-English languages.
  • Custom Pronunciation: New support for inline IPA, giving you control over exact word pronunciations. See the Key Features for details.