Inworld Realtime TTS-2 reaches GA with audio-aware, prompt-directed speech
Confirmed
The takeaway
Inworld AI made Realtime TTS-2 (inworld-tts-2) and TTS-2 Flash generally available on 2026-08-31 after a research preview on 2026-05-05.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- 3 of 5
- Last verified
- 3 October 2026
Your AI and this story
- GPT-6 Astra123 days after its cutoff
- Claude Opus 5.562 days after its cutoff
- Gemini 4 Hydrogen153 days after its cutoff
- Grok 4.792 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 62 days before it.
Key facts
- Oct 1, 2026: Inworld acquired Ultravox, a platform for building real-time voice agents (turn-taking, interruptions); Ultravox customers get Realtime TTS-2; terms not disclosed
- Model id inworld-tts-2; endpoint POST https://api.inworld.ai/tts/v1/voice
- TTS-2 median TTFA <200 ms; Flash ~20 ms TTFB (docs)
- Voice cloning from 5-15 s; voice design from text; STABLE/BALANCED/CREATIVE modes
- Artificial Analysis 29 Sept 2026: #5 (Elo 1244); Inworld’s earlier TTS 1.5 had been #1
- TTS-1..1.5 discontinued 2026-06-15; Inworld also offers migration from shut-down PlayHT
What happened
Inworld promoted TTS-2 from research preview to GA and added a Flash variant for latency- and cost-sensitive agents.
Why it matters
TTS-2 closes the loop between listening and speaking in a cascaded voice stack: the TTS hears the user, not just the transcript. The price is also well under ElevenLabs’ list price.
Sources
5 sources from 4 sites. Numbers match the chips in the text.
5 sources: 3 primary, 2 press
Primary
- Inworld: Realtime TTS-2inworld.ai, official
- Inworld docs: TTS modelsdocs.inworld.ai, docs
- Inworld pricinginworld.ai, official
Press
- Yahoo Finance: AI research lab Inworld acquires Ultravoxfinance.yahoo.com, press
- MarkTechPost: preview launch (2026-05-05)marktechpost.com, press
Changes
- Added the Ultravox acquisition (Oct 1)
- Filed