Developer-first voice AI platform with low-latency LLM-powered phone agents
Retell AI is an LLM-powered voice automation platform for building, deploying, and scaling AI voice agents that handle inbound and outbound phone calls. With ~600ms latency, a drag-and-drop agent builder, and BYO-LLM flexibility (GPT, Claude, Gemini), Retell powers receptionists, lead qualification bots, and large-scale outbound campaigns across healthcare, fintech, insurance, and logistics.
Sub-second response time enables natural, fluent back-and-forth conversations
Choose GPT, Claude, or Gemini models per agent — pay infrastructure cost separately from LLM cost
Visual agentic framework with built-in guardrails and prompt templates
Agents book appointments, process payments, transfer calls, and trigger webhooks during live conversations
Automatic syncing keeps agents grounded in up-to-date documents and FAQs
Run unlimited concurrent outbound campaigns without provisioning constraints (Enterprise)
Performance dashboards, transcripts, sentiment, and call success metrics
24/7 phone answering with appointment booking and call transfers for clinics, agencies, and SMBs
Batch-call leads, qualify intent, and hand off to human reps via warm transfer
HIPAA-compliant reminders, intake, and follow-up calls with PII redaction
Tier-1 voice support with knowledge base RAG and escalation paths

No-code AI voice agents for automated phone calls

The world's most realistic and expressive voice AI with emotional intelligence

AI Agent OS that calls, texts, emails, and chats at enterprise scale

Enterprise-grade neural text-to-speech with 500+ lifelike voices in 140+ languages
Best for developer-led teams and high-volume voice operations that prioritize latency, LLM flexibility, and pay-as-you-go economics over omnichannel breadth.
Best for production phone-call agents where telephony reliability and turn-taking matter more than voice library size.
HIPAA, SOC 2 Type II, GDPR, PII redaction, SSO, and custom roles
Automated driver check-ins, ETA confirmations, and exception handling
AI Voice Generator, Text to Speech & Voice Cloning Platform