258 ms median and 346 ms P95 time to first audio on Coval (30 days to October 22, 2026): Visible delay speed tier.
Benchmark summary: Visible delay speed tier on Coval's P95 (the voice becomes a visible part of the delay).
Rime Mist v3 is a proprietary text-to-speech (TTS) API from Rime, measured by two independent benchmarks: Coval and Speko.
Speed tier
Visible delayP95 of 320 ms or more. The voice becomes a visible part of the delay.
Data read October 22, 2026. No combined score: methodology
Gradium TTS vs Rime Mist v3 Fastest TTS APIs, by speed tierOn Coval's 30-day window ending October 22, 2026 (1,302 runs from US East), Rime Mist v3 starts speaking after 258.1 ms on a typical turn (median) and 346.3 ms on a slow turn (P95, the slowest one in twenty). That P95 is 16th lowest of the 32 models Coval measures, which puts it in the Visible delay tier: the voice becomes a visible part of the delay. On the median it is a tie (gap under 10 ms) with Deepgram Aura 2, Soniox TTS Real-Time v2 and Soniox TTS RT v1. Speko's board plots it at 120 ms time to first audio from US East.
Speko rates its naturalness at 1,428 Elo from blind A/B votes on phone-agent lines (35th highest of the 43 models Speko rates).
Speko has not scored its pronunciation of numbers and dates.
Coval lists $30 per 1M characters (since Aug 10, 2026). Speko lists about $30. List prices, as each source prints them.
Soniox TTS Real-Time v2 is a proprietary text-to-speech (TTS) API from Soniox, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.
Soniox TTS RT v1 is a proprietary text-to-speech (TTS) API from Soniox, measured by two independent benchmarks: Coval and Speko.
Cartesia Sonic 3.6 is a proprietary text-to-speech (TTS) API from Cartesia, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.