Voice AI BenchmarksBy

PROVIDERLAST 30 DAYS

official resource

Inworld AI voice AI models and benchmarks

Inworld AI lists 3 STT and TTS models in Coval. Fastest dated mean latency over 30 days: STT: STT 1 at 67 ms TTFS, with 7.1% WER. TTS: TTS Flash 2 at 91 ms TTFA, with 1.7% WER. Last measured .

Inworld AI builds real-time speech services for interactive applications.

Measured models
3
STTTTS
Best STT model#4 / 29
67ms
STT 1
Best TTS model#4 / 32
91ms
TTS Flash 2

Overview

Recognition, standard synthesis and a latency-oriented Flash variant ship as separate first-party products.

Every model below is measured daily on the same fixed inputs and ranked against the full field, never blended into a company score.

Model lineup

Speech-to-Text
STT 1
Text-to-Speech
TTS 2, TTS Flash 2

Speech-to-Text

Full STT dashboard

Ranked on Time to Final Segment against 29 measured models.

Time to Final Segmentms · lower is better · Inworld AI models markedEvery measured STT model on Time to Final Segment, with Inworld AI's models highlighted.
  1. #1Qwen3 ASR 1.7b39 ms
  2. #2STT RT v545 ms
  3. #3Qwen3 ASR Fast47 ms
  4. #4STT 167 ms
  5. #5Nova 385 ms
  6. #6Nova 287 ms
  7. #7Parakeet TDT 0.6B v397 ms
leaders plus Inworld AI models · 22 other models in the full table
Word Error Rate% · lower is better · Inworld AI models markedEvery measured STT model on Word Error Rate, with Inworld AI's models highlighted.
  1. #1Universal 3.6 Pro2.1%
  2. #2Universal 3.5 Pro2.3%
  3. #3Qwen3 ASR Fast2.6%
  4. #4resonant-12.6%
  5. #5Qwen3 ASR 1.7b2.9%
  6. #6Gemini 3.5 Transcribe Live3.0%
  7. #7Chirp 33.2%
  8. #26STT 17.1%
leaders plus Inworld AI models · 23 other models in the full table
Time to First Tokenms · lower is better · Inworld AI models markedEvery measured STT model on Time to First Token, with Inworld AI's models highlighted.
  1. #1Whisper Large v3via Baseten924 ms
  2. #2Qwen3 ASR 1.7b946 ms
  3. #3Universal 3.5 Pro1026 ms
  4. #4Universal 3.6 Pro1071 ms
  5. #5Flux1092 ms
  6. #6Flux Multilingual1165 ms
  7. #7STT 11208 ms
leaders plus Inworld AI models · 20 other models in the full table
TTFS vs WER — Inworld AI vs every measured modelEach point is one measured STT model · Inworld AI models highlighted · 30-day averagesTime to Final Segment against Word Error Rate for every measured STT model, with Inworld AI's models highlighted.
Qwen3 ASR 1.7b — 39 ms, 2.9%STT RT v5 — 45 ms, 4.8%Qwen3 ASR Fast — 47 ms, 2.6%Nova 3 — 85 ms, 5.3%Nova 2 — 87 ms, 6.7%Parakeet TDT 0.6B v3 — 97 ms, 11.1%Flux Multilingual — 98 ms, 7.5%Flux — 99 ms, 5.8%Scribe v2 Realtime — 122 ms, 4.4%Whisper Large v3 via Baseten — 131 ms, 4.5%Universal 3.6 Pro — 135 ms, 2.1%Ink 2 — 149 ms, 3.6%Universal 3.5 Pro — 168 ms, 2.3%Whisper Large v3 via Together AI — 199 ms, 7.4%Pulse — 205 ms, 4.6%Grok STT — 223 ms, 4.1%resonant-1 — 252 ms, 2.6%Default — 259 ms, 8.8%Linden 1 — 271 ms, 3.9%Gemini 3.5 Transcribe Live — 317 ms, 3.0%Daytona STT — 399 ms, 4.9%Voxtral Mini Transcribe Realtime 2602 — 413 ms, 5.3%GPT Realtime Whisper — 599 ms, 4.0%Solaria 1 — 625 ms, 6.0%GPT-4o mini Transcribe — 708 ms, 3.9%Chirp 3 — 768 ms, 3.2%GPT-4o Transcribe — 784 ms, 3.7%Chirp 2 — 908 ms, 3.9%STT 1 — 67 ms, 7.1%
Benchmarked models with their Time to Final Segment over the last 30 days.
ModelHostTTFSRank
STT 1Inworld AI67 ms4th of 29

Text-to-Speech

Full TTS dashboard

Ranked on Time to First Audio against 32 measured models.

Time to First Audioms · lower is better · Inworld AI models markedEvery measured TTS model on Time to First Audio, with Inworld AI's models highlighted.
  1. #1vui60 ms
  2. #2Default63 ms
  3. #3Qwen3 TTS Fast68 ms
  4. #4TTS Flash 291 ms
  5. #5Qwen3 TTS 1.7b107 ms
  6. #6Simba 3.0111 ms
  7. #7Palabra TTS v1120 ms
  8. #10TTS 2191 ms
leaders plus Inworld AI models · 24 other models in the full table
Word Error Rate% · lower is better · Inworld AI models markedEvery measured TTS model on Word Error Rate, with Inworld AI's models highlighted.
  1. #1Sonic 3.61.5%
  2. #2S2.1 Pro Free1.5%
  3. #3Simba 3.01.5%
  4. #4S2.1 Pro1.5%
  5. #5Lightning v3.1 Pro1.5%
  6. #6Sonic 3.51.5%
  7. #7Chirp 3 HD1.5%
  8. #9TTS 21.6%
  9. #11TTS Flash 21.7%
leaders plus Inworld AI models · 23 other models in the full table
TTFA vs WER — Inworld AI vs every measured modelEach point is one measured TTS model · Inworld AI models highlighted · 30-day averagesTime to First Audio against Word Error Rate for every measured TTS model, with Inworld AI's models highlighted.
vui — 60 ms, 2.1%Default — 63 ms, 1.9%Qwen3 TTS Fast — 68 ms, 1.8%Qwen3 TTS 1.7b — 107 ms, 1.8%Simba 3.0 — 111 ms, 1.5%Palabra TTS v1 — 120 ms, 2.6%Simba 3.2 — 126 ms, 1.9%drama3-preview — 168 ms, 2.0%Flash v2.5 — 191 ms, 1.8%Eleven v4 Turbo — 201 ms, 1.7%Flux TTS — 205 ms, 1.7%TTS RT v1 — 254 ms, 2.4%TTS Rt v2 — 256 ms, 2.4%Mist v3 — 287 ms, 2.1%Sonic 3.5 — 293 ms, 1.5%Phantom Z 3.4 conversational — 293 ms, 1.8%Aura 2 — 297 ms, 1.8%Sonic 3.6 — 299 ms, 1.5%Falcon 2 — 301 ms, 1.7%Coda — 332 ms, 9.5%S2.1 Pro — 341 ms, 1.5%Grok TTS — 362 ms, 1.6%S1 — 389 ms, 1.8%Lightning v3.1 Pro — 393 ms, 1.5%Daytona TTS — 486 ms, 1.6%Aura 2 En — 570 ms, 2.1%Chirp 3 HD — 597 ms, 1.5%Qwen3 TTS Flash Realtime — 718 ms, 3.0%S2.1 Pro Free — 849 ms, 1.5%GPT-4o mini TTS — 2581 ms, 1.8%TTS Flash 2 — 91 ms, 1.7%TTS 2 — 191 ms, 1.6%
Benchmarked models with their Time to First Audio over the last 30 days.
ModelHostTTFARank
TTS 2Inworld AI191 ms10th of 32
TTS Flash 2Inworld AI91 ms4th of 32

How fast are Inworld AI's STT and TTS models?

STT 1 measures mean 67 ms time to final segment (4th of 29) among STT systems. Last measured 2026-10-14. TTS Flash 2 measures mean 91 ms time to first audio (4th of 32) among TTS systems. Last measured 2026-10-14. TTS 2 measures mean 191 ms time to first audio (10th of 32) among TTS systems. Last measured 2026-10-14.

How accurate are Inworld AI's STT and TTS models?

STT 1 measures 7.1% word error rate (26th of 31) among STT systems. Last measured 2026-10-14. TTS 2 measures 1.6% word error rate (9th of 32) among TTS systems. Last measured 2026-10-14. TTS Flash 2 measures 1.7% word error rate (11th of 32) among TTS systems. Last measured 2026-10-14.

Which Inworld AI model is fastest?

Its fastest dated STT result is STT 1 at mean 67 ms time to final segment (4th of 29) among STT systems, with 7.1% WER. Last measured 2026-10-14. Its fastest dated TTS result is TTS Flash 2 at mean 91 ms time to first audio (4th of 32) among TTS systems, with 1.7% WER. Last measured 2026-10-14.

Limits of this comparison

Coval measures its STT 1 recognizer and both standard and Flash variants of TTS 2.

  • Coval does not score character intelligence, game integration or other layers of Inworld's platform.

Official resources

Same datasets, prompts and metric definitions for every model, measured by Coval’s open-source runner. Full methodology on the overview.

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