Speed tier
19 text-to-speech (TTS) models, ordered speed first: by speed tier and P95 time to first audio on Coval, then the models Coval does not measure, by name. No combined score.
Data checked on October 22, 2026 · updated after each benchmark capture
19 text-to-speech (TTS) models are in the Visible delay speed tier: P95 of 320 ms or more on Coval's 30-day window, measured from US East. The voice becomes a visible part of the delay.
Coval calls each hosted API every 30 minutes and publishes percentiles over 30 days. The tiers group models on the P95 time to first audio, the slowest one turn in twenty, and break where the data has gaps. Within a tier, latencies within 10 ms are a tie. Voice quality, accuracy and price are compared on the model pages, never added into one score.
Alibaba Qwen3 TTS Flash Realtime is a proprietary text-to-speech (TTS) API from Alibaba (Qwen), measured by one independent benchmark, Coval.
Cartesia Sonic 3.5 is a proprietary text-to-speech (TTS) API from Cartesia, measured by three independent benchmarks: Artificial Analysis, 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.
Deepdub Phantom Z 3.4 conversational is a proprietary text-to-speech (TTS) API from Deepdub, measured by one independent benchmark, Coval.
Deepgram Aura 2 is a proprietary text-to-speech (TTS) API from Deepgram, measured by two independent benchmarks: Coval and Speko.
Deepgram Aura 2 En is a proprietary text-to-speech (TTS) API from Deepgram, served by Cloudflare, measured by one independent benchmark, Coval.
Fish Audio S2.1 Pro is a proprietary text-to-speech (TTS) API from Fish Audio, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.
Fish Audio S2.1 Pro Free is a proprietary text-to-speech (TTS) API from Fish Audio, measured by one independent benchmark, Coval.
Google Chirp 3: HD is a proprietary text-to-speech (TTS) API from Google, measured by two independent benchmarks: Artificial Analysis and Coval.
Guava Daytona TTS is an open-weights text-to-speech (TTS) API from Guava, measured by one independent benchmark, Coval.
Murf AI Falcon 2 is a proprietary text-to-speech (TTS) API from Murf AI, measured by two independent benchmarks: Artificial Analysis and Coval.
OpenAI GPT-4o mini TTS is a proprietary text-to-speech (TTS) API from OpenAI, measured by two independent benchmarks: Coval and Speko.
Out of Set Airy TTS is a proprietary text-to-speech (TTS) API from Out of Set, measured by two independent benchmarks: Coval and Speko.
Rime Coda is a proprietary text-to-speech (TTS) API from Rime, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.
Rime Mist v3 is a proprietary text-to-speech (TTS) API from Rime, measured by two independent benchmarks: Coval and Speko.
Smallest.ai Lightning V3.1 Pro (Jul 2026) is a proprietary text-to-speech (TTS) API from Smallest.ai, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.
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.
SpaceXAI Grok TTS is a proprietary text-to-speech (TTS) API from xAI, measured by three independent benchmarks: Artificial Analysis, Coval and Speko.