Twilio ConversationRelay vs Vapi

It depends on usage. Vapi's base rate is $0.05/min versus Twilio ConversationRelay's $0.07/min, so Vapi starts lower. However, real production costs tell a different story: Vapi's actual range runs $0.05-$0.17/min depending on LLM and TTS choices, while Twilio ConversationRelay lands in a tighter $0.079-$0.084/min range. For heavy or unpredictable AI model usage, Twilio ConversationRelay can end up more predictable, and sometimes cheaper, than Vapi.

Vapi is the stronger fit for no-code agency deployments. It offers a no-code agent builder, native outbound campaigns, warm transferwarm transfer - Handing a live call to a human with context passed along, rather than a cold drop. to human, a built-in knowledge base, and partial white-label support for sub-accounts. Native integrations include GHL, Zapier, Make, Slack, and Google Calendar. Twilio ConversationRelay is API-first and developer-oriented, with no documented no-code builder, making it better suited to engineering teams than agencies managing client accounts.

Twilio ConversationRelay reports a median end-to-end latency of 491 ms, while Vapi reports 600 ms. For latency-sensitive use cases like real-time customer service, Twilio ConversationRelay currently holds the edge based on published figures. Both numbers are vendor-claimed, so testing in your own environment is recommended.

Both Vapi and Twilio ConversationRelay offer HIPAAHIPAA BAA - A signed Business Associate Agreement that lets you handle protected health information under US healthcare privacy law. BAAs, but neither includes one on the base plan. In both cases it is a paid add-on, so healthcare teams should budget for that extra cost on top of standard usage fees.

Twilio ConversationRelay holds a verified SOC 2 Type IISOC 2 Type II - An independent audit confirming the vendor’s security controls operated effectively over a period of time. certification, while Vapi does not currently have one. This is a meaningful difference for enterprise security reviews or procurement checklists.

Twilio ConversationRelay has a base rate of $0.07/min plus a small additional telephony charge of $0.0085/min (roughly $0.51/hr). LLM and TTS costs are passed through at cost on top of that. Real production costs are estimated at about $0.079 to $0.084 per minute all-in before LLM and TTS.

Vapi includes 10 concurrent calls on the base plan. Going beyond that costs $10 per month for each additional concurrent line. Teams running high-volume outbound campaigns should factor this into their scaling budget alongside per-minute usage fees.

Yes. Vapi includes 60+ free minutes on signup. Twilio ConversationRelay offers a free trial credit on signup. Both platforms also support self-serve signup with no sales call required, so you can start testing the same day.

Vapi supports native outbound campaigns, a built-in knowledge base, warm transferwarm transfer - Handing a live call to a human with context passed along, rather than a cold drop. to human agents, and a simulation and testing suite. Twilio ConversationRelay is API-first and connects to any LLM via WebSocket, but these higher-level workflow features are not listed among its published capabilities.

Both platforms support bring-your-own LLMBYO LLM - Bring your own language model - use an OpenAI, Anthropic, or self-hosted endpoint instead of the platform default.. Twilio ConversationRelay connects to any LLM via WebSocket, and Vapi also lets you supply your own LLM. Both pass LLM and TTS costs through at cost, with no markup.