Retell AI
AI sales assistant software
General-purpose AI agents
Agentic AI software
AI agent builders software
AI agents
AI customer support agents software
AI voice assistants
AI person generator tools
AI avatar video generator tools
AI lip sync generator tools
- Features
- Ease of use
- Ease of management
- Quality of support
- Affordability
- Market presence
Take the quiz to check if Retell AI and its alternatives fit your requirements.
Pay-as-you-go
Free Trial
Free version unavailable
Small
Medium
Large
- Real estate and property management
- Information technology and software
- Transportation and logistics
What is Retell AI
Retell AI is a platform for building and operating AI voice agents that can handle real-time phone conversations for customer support, scheduling, and sales workflows. It provides APIs and tooling to connect speech-to-text/text-to-speech, large language models, and telephony so teams can deploy voice agents into existing business systems. Typical users include product and engineering teams, contact-center operators, and revenue operations teams that want to automate inbound and outbound calls. The product emphasizes programmable agent behavior, call flows, and integrations rather than a full CRM suite.
Voice-first, real-time calling
Retell AI focuses on low-latency voice conversations, which is a core requirement for phone-based support and sales use cases. It is designed to connect to telephony and handle live call control rather than only chat-based interactions. This makes it suitable for organizations that need AI agents to operate on phone channels alongside human agents. It can complement CRM-centric tools in the reference set by automating the voice layer without replacing the CRM.
Developer-oriented APIs and tooling
The platform is positioned as an API-first system for building voice agents, which can fit engineering-led teams that want custom logic and integrations. This approach can reduce dependence on rigid, prepackaged workflows common in sales suites. It supports programmatic configuration and integration patterns that are useful for embedding agents into existing applications. It is typically adopted as an infrastructure component rather than an end-user CRM.
Integration-friendly for business workflows
Retell AI is commonly used where the voice agent must read/write data in external systems (e.g., ticketing, scheduling, lead routing, or internal databases). This enables automation of tasks such as qualification, appointment booking, and status updates during or after calls. It can be deployed alongside existing sales and support stacks rather than requiring a full platform migration. The product’s value is strongest when integrated into a broader workflow ecosystem.
Not a full sales suite
Retell AI does not present as a full CRM with pipeline management, forecasting, and native sales analytics comparable to established sales platforms. Organizations looking for an all-in-one sales workspace may still need separate systems for lead management and reporting. As a result, it often requires integration work to fit into end-to-end revenue operations. Buyers should evaluate total solution scope beyond the voice agent layer.
Engineering effort for customization
Because it is oriented around APIs and configurable agent behavior, implementation can require technical resources for integration, testing, and ongoing tuning. Teams without engineering support may find it harder to deploy compared with packaged sales tools. Operationalizing voice agents also involves monitoring, prompt/flow iteration, and handling edge cases. This can increase time-to-value for non-technical organizations.
Limited fit for avatar tools
Despite overlap in broader ‘AI agent’ categories, Retell AI is primarily a voice agent platform and is not typically evaluated as an AI avatar video, lip-sync, or person-generation tool. Buyers seeking video avatar generation capabilities may need separate specialized products. This can create a multi-vendor architecture if both voice automation and avatar video content are required. Category alignment should be validated against the intended channel (phone vs. video).
Plan & Pricing
Pricing model: Pay-as-you-go Free tier/trial: $10 in free credits (approx. 60 minutes) + 20 free concurrent calls + 10 free Knowledge Bases (trial/free credits provided on sign-up). Example costs (official site components):
- Retell Voice infra: $0.055/minute.
- Text-to-Speech voices (Cartesia / Minimax / ElevenLabs): $0.015/minute each.
- Telephony (Retell Twilio): $0.015/minute (US); US toll-free $0.06/min; international rates vary by country (site lists country-specific rates).
- LLM per-minute options (selected examples): GPT 5 $0.04/min (Fast Tier $0.08/min); GPT 5 mini $0.012/min (Fast $0.024); GPT 5 nano $0.003/min; GPT 4.1 $0.045/min (Fast $0.0675); GPT 4o $0.05/min (Fast $0.075); GPT 4o mini $0.006/min; Claude 4.5 sonnet $0.08/min; Claude 3.5 haiku $0.02/min; Gemini 2.0 Flash $0.006/min; GPT 4o Realtime $0.50/min; GPT 4o mini Realtime $0.125/min.
- Chat agent (per-AI-message) examples: GPT 4.1 $0.015/AI msg; GPT 4.1 mini $0.006/msg; GPT 4.1 nano $0.002/msg; GPT 4o $0.017/msg; GPT 5 $0.013/msg; Gemini 2.0 Flash $0.006/msg; etc.
- Call agent add-ons: Knowledge Base +$0.005/min; Batch Call +$0.005/dial; Branded Call +$0.10/outbound call; Advanced Denoising +$0.005/min; PII Removal +$0.01/min.
- Monthly subscription items: Retell Phone Numbers $2.00/month; Retell SMS $20.00/month; Concurrency $8.00/concurrency/month (first 20 concurrency free); Knowledge Base $8.00/KB/month (first 10 KBs free); Verified Phone Number $10 one-time fee.
Discount options / Enterprise: Contact Sales for Enterprise plan; site references volume discounts (examples on site: "as low as $0.05/min" at scale) and optional white-glove services/SLAs.
Notes / Billing model details: Site states "No platform fees" and "Pay only for what you use." The site also provides a pricing calculator to compose the total per-minute cost by summing Retell infra + chosen LLM + TTS + telephony. Prompts exceeding 3,500 tokens may incur a surcharge (per site).
