Founded

2023

Starting Price

$0.07

About Retell AI

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.

Pros & Cons

Pros

Industry-leading ~600ms latency makes conversations feel genuinely natural
BYO-LLM flexibility lets you tune cost vs quality per agent (GPT-4o, Claude, Gemini)
Pure pay-as-you-go pricing with no monthly minimum — start at $0
Strong developer tooling: APIs, webhooks, SIP trunking, and SDKs
Enterprise-grade compliance baseline (HIPAA, SOC 2, GDPR) even on lower tiers

Key Features

Low-Latency Voice (~600ms)

Sub-second response time enables natural, fluent back-and-forth conversations

BYO-LLM Architecture

Choose GPT, Claude, or Gemini models per agent — pay infrastructure cost separately from LLM cost

Drag-and-Drop Agent Builder

Visual agentic framework with built-in guardrails and prompt templates

Real-Time Function Calling

Agents book appointments, process payments, transfer calls, and trigger webhooks during live conversations

Knowledge Base + Streaming RAG

Automatic syncing keeps agents grounded in up-to-date documents and FAQs

Batch Calling

Run unlimited concurrent outbound campaigns without provisioning constraints (Enterprise)

Post-Call Analytics

Performance dashboards, transcripts, sentiment, and call success metrics

Pricing

Pay-as-You-Go

$0.07/minute

$10 free credits to start
20 concurrent calls included
Voice: $0.07-$0.31/min (LLM dependent)
Chat: $0.002+ per message
Full platform access, no contracts

Best For

AI Receptionist

24/7 phone answering with appointment booking and call transfers for clinics, agencies, and SMBs

Outbound Lead Qualification

Batch-call leads, qualify intent, and hand off to human reps via warm transfer

Healthcare Patient Outreach

HIPAA-compliant reminders, intake, and follow-up calls with PII redaction

Customer Support Automation

Tier-1 voice support with knowledge base RAG and escalation paths

Tags:voice-ai ai-phone-agent llm-voice developer-platform outbound-calling

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Retell AI