Uploaded January 2026 | Updated September 2026, 43 minutes ago
Say goodbye to robotic-sounding IVRs 👋
In this video, you’ll see how to plug ElevenLabs into Twilio ConversationRelay so your Twilio Voice agents can talk, listen, and respond in a natural, human-like voice.
You’ll learn how to:
- Clone and run the ConversationRelay demo app (Node.js + Fastify + WebSockets)
- Expose your local server with ngrok so Twilio can reach it
- Configure your .env with OpenAI, Twilio Account SID, and ngrok URL
- Pick and customize an ElevenLabs voice (voice ID, model, speed, stability, similarity)
- Build the full ElevenLabs voice string (ID + model + parameters)
- Wire your Twilio phone number to your /twiml webhook
- Call your number and hear your AI assistant answer in an ElevenLabs voice
- Behind the scenes architecture
FAQs:
What is Twilio ConversationRelay?
ConversationRelay is a Twilio feature that lets you integrate speech-to-text, text-to-speech, and LLMs directly into Twilio Voice, handling real-time audio streaming and interruption so you can focus on app logic.
Can I use ElevenLabs voices in Twilio Voice?
Yes. By setting ttsProvider="ElevenLabs" and providing an ElevenLabs voice string in your ConversationRelay TwiML, you can use ElevenLabs voices on Twilio phone calls.
How do I pick an ElevenLabs voice for Twilio?
Choose a voice in the ElevenLabs UI, copy its voice ID, select a model (e.g. flash_v2_5 or turbo_v2_5) and tune parameters like speed, stability, and similarity. Combine them into one voice string and paste it into your TwiML.
Does ElevenLabs TTS work in real time with ConversationRelay?
Yes. ConversationRelay streams caller audio, sends text to your LLM, then uses ElevenLabs to read the response back with low latency, keeping the whole loop in sync.
🔗 Demo app (ConversationRelay + ElevenLabs tutorial code):
github.com/robinske/cr-demo
💻 Sign up for a Twilio account here: twil.io/trytwilio-yt
👉 Subscribe for more Twilio updates: twil.io/sub-twiliodevs
Chapters:
00:00 Intro
00:39 Setting up our application
01:16 Exposing our local server with NGROK
01:31 Updating .env
02:04 Choosing an ElevenLabs voice
02:32 Customizing your ElevenLabs voice
03:22 Updating our app to use an ElevenLabs voice
04:02 Connecting our Twilio phone number
04:47 How ConversationRelay works behind the scenes
05:12 Outro and Next Steps
#twilio #elevenlabs #conversationrelay #twiliovoice #texttospeech #aiagent #voicebot #openai #nodejs #websockets #ivr #aiassistant
Say goodbye to robotic-sounding IVRs 👋
In this video, you’ll see how to plug ElevenLabs into Twilio ConversationRelay so your Twilio Voice agents can talk, listen, and respond in a natural, human-like voice.
You’ll learn how to:
- Clone and run the ConversationRelay demo app (Node.js + Fastify + WebSockets)
- Expose your local server with ngrok so Twilio can reach it
- Configure your .env with OpenAI, Twilio Account SID, and ngrok URL
- Pick and customize an ElevenLabs voice (voice ID, model, speed, stability, similarity)
- Build the full ElevenLabs voice string (ID + model + parameters)
- Wire your Twilio phone number to your /twiml webhook
- Call your number and hear your AI assistant answer in an ElevenLabs voice
- Behind the scenes architecture
FAQs:
What is Twilio ConversationRelay?
ConversationRelay is a Twilio feature that lets you integrate speech-to-text, text-to-speech, and LLMs directly into Twilio Voice, handling real-time audio streaming and interruption so you can focus on app logic.
Can I use ElevenLabs voices in Twilio Voice?
Yes. By setting ttsProvider="ElevenLabs" and providing an ElevenLabs voice string in your ConversationRelay TwiML, you can use ElevenLabs voices on Twilio phone calls.
How do I pick an ElevenLabs voice for Twilio?
Choose a voice in the ElevenLabs UI, copy its voice ID, select a model (e.g. flash_v2_5 or turbo_v2_5) and tune parameters like speed, stability, and similarity. Combine them into one voice string and paste it into your TwiML.
Does ElevenLabs TTS work in real time with ConversationRelay?
Yes. ConversationRelay streams caller audio, sends text to your LLM, then uses ElevenLabs to read the response back with low latency, keeping the whole loop in sync.
🔗 Demo app (ConversationRelay + ElevenLabs tutorial code):
github.com/robinske/cr-demo
💻 Sign up for a Twilio account here: twil.io/trytwilio-yt
👉 Subscribe for more Twilio updates: twil.io/sub-twiliodevs
Chapters:
00:00 Intro
00:39 Setting up our application
01:16 Exposing our local server with NGROK
01:31 Updating .env
02:04 Choosing an ElevenLabs voice
02:32 Customizing your ElevenLabs voice
03:22 Updating our app to use an ElevenLabs voice
04:02 Connecting our Twilio phone number
04:47 How ConversationRelay works behind the scenes
05:12 Outro and Next Steps
#twilio #elevenlabs #conversationrelay #twiliovoice #texttospeech #aiagent #voicebot #openai #nodejs #websockets #ivr #aiassistant
