Retell vs. Vapi vs. LiveKit: A Developer Comparison for Voice AI Agents

LiveKit published a developer-focused comparison of Retell, Vapi and LiveKit for building voice AI agents, framing the choice around four questions: who iterates on the agent after launch, what happens when needs fall outside defaults, whether it must run beyond phone calls, and cost at scale. Retell is a managed platform with a visual editor, Vapi a developer-oriented managed platform configured via API and dashboard, and LiveKit an Apache 2.0 open source framework with self-hosting. Estimated all-in cost per minute runs about $0.070–$0.310 for Retell, $0.070–$0.116 for Vapi and $0.037–$0.099 for LiveKit.