Retell AI vs Vapi

Retell AI and Vapi are the two most commonly shortlisted developer-first platforms for building AI phone agents, and they overlap heavily: both give you streaming voice infrastructure, telephony hooks, and your choice of LLM and text-to-speech provider on a usage-based bill.

Verdict

Vapi is the more modular, build-it-yourself option with pass-through pricing on each component, which rewards teams that want to swap providers and squeeze cost. Retell AI is slightly more opinionated and packaged, with a stronger out-of-the-box compliance story (SOC 2, HIPAA, GDPR with a self-serve BAA) that matters for healthcare and regulated call centres. For most teams the real decision comes down to trialling both with your own prompts and phone traffic, since latency and voice quality vary by configuration more than by platform.

Choose Retell AI if…

you need HIPAA or GDPR compliance out of the box and want a somewhat more packaged platform with predictable per-minute pricing.

Choose Vapi if…

you want maximum control over every layer of the voice stack and near-cost, pass-through pricing on each component.