Retell AI, founded in 2023, builds AI voice agents specifically for phone calls, answering inbound calls, placing outbound calls, booking appointments, and qualifying leads autonomously, a narrower and more specific focus than the omnichannel messaging-and-voice platforms also covered in this category.
Its latency is the more distinctive technical claim: roughly 600 milliseconds response time, notably fast for a phone conversation where any longer delay starts to feel unnatural, paired with real-time function calling for booking and payment processing and simulation testing before an agent goes live on real calls.
A pay-as-you-go plan starts at $0.07 a minute with $10 in free credits to start, and an Enterprise tier starts around $8,000 for fully managed, high-volume deployments. For a team that specifically needs low-latency AI phone agents, rather than a broader omnichannel platform where voice is one channel among several, Retell AI's phone-first focus and fast response time address that directly.
