Vapi vs Retell AI: What You Need to Know
The two developer voice-API rivals: Vapi's maximum flexibility vs Retell's itemized transparency — both leave you building the CRM, calendar and whitelabel layer yourself.
Vapi
Vapi is a developer-first API platform for building custom voice AI agents, where you assemble and host your own voice stack.
- +You're an engineering team building a custom voice product
- +You need component-level control (custom STT/TTS pipelines, custom orchestration)
- +You have developers on staff to own setup and maintenance
Retell AI
Retell AI is developer infrastructure for building voice and chat AI agents, priced per minute from unbundled components.
- +You're a developer who values itemized infrastructure pricing
- +You're building your own product on voice rails, not delivering client front offices
- +You want granular control of every pipeline component
Vapi vs Retell AI vs SeldonFrame
| Features | Vapi | Retell AI | SeldonFrame |
|---|---|---|---|
| Best for | Engineering teams building custom voice stacks | Developers building custom voice/chat agents on API rails | Agencies & builders running AI front offices for clients |
| Pricing model | $0.05/min hosting + STT/LLM/TTS/telephony pass-through (~$0.25–$0.33/min real-world); HIPAA $2,000/mo | $0.07–$0.31/min all-in, plus per-minute add-ons (KB, guardrails, PII, QA) and monthly fees per number | $29/mo flat — unlimited workspaces, no per-feature add-ons |
| AI receptionist (calls, SMS, chat) | Voice agents only — you design, integrate and maintain them via API | Voice + chat agents via API — you build the receptionist yourself | Native — AI receptionist answers, qualifies & books across voice, SMS & web chat |
| Website, CRM & booking behind the agent | None — no CRM, website or booking calendar; you build the system around the agent | None — no CRM, website or booking calendar | Included — multi-page website, CRM, booking calendar, intake forms, review requests in every workspace |
| Whitelabel & client workspaces | None — no agency dashboard or client management | None native — third-party wrapper products fill the gap | Included — whitelabel client portal, per-client workspaces, custom domains, one-click multi-client deploy |
| AI usage costs | BYO API key possible, but every other component still meters per minute | Metered per minute per component | BYOK — bring your own AI (and Twilio) keys and pay providers at raw cost, zero markup |
| Sell / resell what you build | No native reseller program | Certified-partner referrals, but no native whitelabel product | Built in — publish agents to the marketplace or rent them via MCP (5% marketplace fee) |
Need what both Vapi and Retell AI do?
Most people running this comparison actually need the outcome underneath both tools: calls and chats answered, leads qualified, jobs booked into a real calendar and CRM, on a site the client owns. SeldonFrame ships that whole front office from one conversation — $29/mo flat, unlimited workspaces, your own AI keys at raw cost, whitelabel included.