{
 "publisher": "Coval",
 "board": "https://benchmarks.coval.ai/tts",
 "harness": "https://github.com/coval-ai/benchmarks",
 "methodology": "https://github.com/coval-ai/benchmarks/blob/main/docs/methodology.md",
 "provenance": "SpeechifyAI's reading of Coval's public results API (/v2/results), the per-request rows behind benchmarks.coval.ai, produced by Coval's open-source harness, whose workers run in us-east-1 (harness README). Every TTS model Coval's /v1/providers lists as enabled, TTFA rows only, with the API's public defaults (successful evaluations, default variant), captured from 2026-10-08T11:00:00Z (inclusive) to 2026-10-09T11:00:00Z (exclusive), every page followed to the end. Read on 9 Oct 2026, inside the API's rolling retention. This is Coval's measurement, not ours: we quote it for Inworld, which our own round did not measure, and set Simba 3.2's row from the same window beside it.",
 "metric": "TTFA = (first audio chunk arrival - synthesis start) + leading silence inside the stream before the first audible sample, in milliseconds, as Coval's methodology defines it. medianTtfa is the median over the window and runs the number of TTFA measurements in it, one per synthesized item.",
 "capturedOn": "2026-10-09",
 "date": "9 Oct 2026",
 "window": {
  "since": "2026-10-08T11:00:00Z",
  "until": "2026-10-09T11:00:00Z",
  "label": "24 h to 9 Oct 11:00 UTC"
 },
 "notes": "Baseten's qwen3-tts-1.7b is left out: its 96 rows in the window all fall in one burst between 04:21 and 04:32 UTC, while every other model's rows spread across the whole day. The API returned no TTFALeadingSilence rows in this window, so this snapshot carries no leading silence. Coval's own board may show a different window.",
 "models": [
  {
   "provider": "Fluxions",
   "model": "vui",
   "medianTtfa": 41.5,
   "runs": 96
  },
  {
   "provider": "Gradium",
   "model": "gradium-tts-beta-202609",
   "medianTtfa": 56.0,
   "runs": 96
  },
  {
   "provider": "Nari",
   "model": "qwen3-tts-fast",
   "medianTtfa": 62.0,
   "runs": 96
  },
  {
   "provider": "Inworld",
   "model": "inworld-tts-2-flash",
   "medianTtfa": 62.3,
   "runs": 96
  },
  {
   "provider": "SpeechifyAI",
   "model": "simba-3.0",
   "medianTtfa": 98.2,
   "runs": 96,
   "ours": true
  },
  {
   "provider": "Palabra",
   "model": "palabra-tts-v1",
   "medianTtfa": 101.1,
   "runs": 80
  },
  {
   "provider": "SpeechifyAI",
   "model": "simba-3.2",
   "medianTtfa": 109.1,
   "runs": 96,
   "ours": true
  },
  {
   "provider": "Inworld",
   "model": "inworld-tts-2",
   "medianTtfa": 146.4,
   "runs": 96
  },
  {
   "provider": "ElevenLabs",
   "model": "eleven_flash_v2_5",
   "medianTtfa": 186.5,
   "runs": 94
  },
  {
   "provider": "ElevenLabs",
   "model": "eleven_v4_turbo",
   "medianTtfa": 190.8,
   "runs": 96
  },
  {
   "provider": "Deepgram",
   "model": "flux-haley-en",
   "medianTtfa": 196.1,
   "runs": 94
  },
  {
   "provider": "Deepdub",
   "model": "dd-etts-3.3",
   "medianTtfa": 213.6,
   "runs": 96
  },
  {
   "provider": "Murf AI",
   "model": "falcon-2",
   "medianTtfa": 233.8,
   "runs": 96
  },
  {
   "provider": "Deepgram",
   "model": "aura-2-thalia-en",
   "medianTtfa": 248.2,
   "runs": 96
  },
  {
   "provider": "Soniox",
   "model": "tts-rt-v1",
   "medianTtfa": 261.3,
   "runs": 80
  },
  {
   "provider": "Soniox",
   "model": "tts-rt-v2",
   "medianTtfa": 265.5,
   "runs": 80
  },
  {
   "provider": "Cartesia",
   "model": "sonic-3.5",
   "medianTtfa": 277.5,
   "runs": 96
  },
  {
   "provider": "Cartesia",
   "model": "sonic-3.6",
   "medianTtfa": 281.2,
   "runs": 96
  },
  {
   "provider": "Fish Audio",
   "model": "s2.1-pro",
   "medianTtfa": 297.1,
   "runs": 96
  },
  {
   "provider": "ElevenLabs",
   "model": "eleven_v3_conversational",
   "medianTtfa": 324.1,
   "runs": 94
  },
  {
   "provider": "xAI",
   "model": "grok-tts",
   "medianTtfa": 328.4,
   "runs": 96
  },
  {
   "provider": "Smallest AI",
   "model": "lightning_v3.1_pro",
   "medianTtfa": 371.1,
   "runs": 96
  },
  {
   "provider": "Fish Audio",
   "model": "s2.1-pro-free",
   "medianTtfa": 381.3,
   "runs": 96
  },
  {
   "provider": "Fish Audio",
   "model": "s1",
   "medianTtfa": 391.0,
   "runs": 96
  },
  {
   "provider": "Google",
   "model": "chirp-3-hd",
   "medianTtfa": 541.2,
   "runs": 96
  },
  {
   "provider": "Cloudflare",
   "model": "aura-2-en",
   "medianTtfa": 591.9,
   "runs": 96
  },
  {
   "provider": "Alibaba",
   "model": "qwen3-tts-flash-realtime",
   "medianTtfa": 722.3,
   "runs": 96
  },
  {
   "provider": "OpenAI",
   "model": "gpt-4o-mini-tts",
   "medianTtfa": 2510.1,
   "runs": 96
  }
 ]
}