Build Advanced Voice AI, Powered by LLM
Retell is the infrastructure for building LLM-based conversational voice AI that interacts and performs tasks like humans
Backed by
// Feel the state-of-the-art Voice Interaction

See A Live Demo With
A Dental Office

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// Experience Magical Conversations with AI That Feel Real

Talk to AI as You Would
Talk to a Person

Ultra-Realistic Voices with Emotions
Human-like voices make conversational interactions more engaging and lifelike.
Interruption Handling and end-of-turn detection
An intelligent mechanism recognizes when a speaker's turn ends and when interruptions occur, ensuring a smooth transition between speakers.
~800ms Low Latency
Experience lightning-fast interactions with approximately one-second latency, ensuring conversations flow as naturally and seamlessly as in real life.
// Full control for diverse use cases.

Highly Configurable
In Each Part

Voice stability control
Control agent's expressiveness
Signal that the agent is listening.
Live ASR Transcript
You can show the Live transcript in your frontend
Add custom voices
Support voice clone
Add ambient noise
Add keywords
Bias ASR toward certain keywords
End-of-turn sensitivity
Idle detection
Speaking rate control
Conversationalization of text responses
Coming soon
Sentiment analysis
Coming soon
Custom tone and emotion
Change to  different tone and emotion based on scenarios
Coming soon
// Built by developers, for developers

Easy Integration
with Your LLM and frontend

// Testmonial

People who love Retell AI

// Inspired by use cases

Trusted by developers

Built on Retell AI's API
70+ Businesses
Saved time for developers
10,000+ h
"Retell AI has been crucial in our product's development, saving us hundreds of development hours."
Elith Palomino
CTO at Avvy
"We loved working with Retell AI's team. We found Retell's API stable which is crucial for maintaining reliability in real-time applications. "
CTO at Permian AI


How does Retell AI differentiate from competitors?
While our competitors might offer many integrations and telephony features, we focus most of our energy on innovating the AI conversation experience, making it more magical day by day. We pride ourselves on wowing our customers when they experience our product themselves.

Retell AI has the best support for "bring your own LLM." We believe that developers building a great AI application should own their own LLM. However, we will provide guidance and best practices to help developers achieve a great AI conversation experience with their own LLM.

We offer full configurability in each step for developers to have maximum control for various use cases.
How can I try it?
The fastest way to try it is to go to our dashboard and create an agent using a prompt. No code is needed, and you can even connect the agent to a phone number. If you want to try it in production, feel free to self-serve by reading the documentation with tutorials or contact us.
I'm not sure about how to handle certain tasks with my LLM. Could you offer some guidance?
Definitely! We're excited to help you in building a high-performance LLM for voice AI, following best practices. We've also made our demo LLM (the same one featured in our dashboard) available as an open-source resource for your reference.
Can I connect Twilio with Retell AI to make phone calls?
Yes, of course! We provide an open-source demo repo to help you set up Twilio quickly. You are also free to use other providers like Vonage, among others.
Is Retell AI compliant with SOC2 and HIPAA regulations?
Your privacy and security are our top priorities. We are proud to be HIPAA compliant. Additionally, we are in the process of obtaining our SOC2 Type II certification. Stay tuned for updates on our compliance journey!
Use the playground to create an agent in 5 minutes before using the API.