Telnyx

Telnyx native TTS models across latency, quality, language coverage, and expressive control.

Selecting Telnyx

Telnyx is the default provider. If you don’t specify a provider, you get Telnyx.

WebSocket:

wss://api.telnyx.com/v2/text-to-speech/speech?voice=Telnyx.NaturalHD.astra

REST:

curl --request POST \
  --url https://api.telnyx.com/v2/text-to-speech \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "text": "Hello.",
  "voice": "Telnyx.NaturalHD.astra"
}'

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Models

Model	Latency	Quality	Languages	Voice Source	WebSocket	REST
Natural	Low	Good	English	Pre-built (Rime Mist)	Yes	Yes
NaturalHD	Low	Better	9 languages	Pre-built (Rime Arcana)	Yes	Yes
KokoroTTS	Lowest	Good	5 languages	Pre-built	Yes	Yes
Qwen3TTS	Medium	High	11 languages	Cloned (Voice Design Lab)	Yes	Yes
Ultra	Lowest	Highest	44 languages	Pre-built	No	Yes
Grok	Higher	High	20+ languages	Pre-built	Voice AI	Yes

Ultra is REST-only, not available over public WebSocket. Grok is available for Voice AI Assistants and direct REST TTS calls.

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Browse all available voices via the Voices API or the Voice Design Lab.