Retell AI vs Vapi — which voice AI platform should you build on?
A head-to-head comparison of Retell AI and Vapi across pricing, latency, telephony, multilingual support, integrations and developer experience.
Retell AI and Vapi both ship production voice agents, but they target different teams. Retell is the faster path for non-engineers — visual flows, managed telephony and built-in analytics. Vapi is the better choice if you have engineers and need full code-level control of the call lifecycle, custom LLM routing and a deeper webhook surface. For ROI-heavy outbound use cases in regulated markets (India banking, real estate, healthcare), most teams hit the wall on language coverage and need a managed partner like Kallix on top of either base.
Products at a glance
Retell AI
Retell AI, Inc.
Managed voice AI platform with a visual flow builder, bundled telephony, prompt-only agent design and a dashboard for non-engineers.
- Pricing from
- $0.07 per minute
- Founded
- 2024
- HQ
- San Francisco, CA
Vapi
Vapi Labs, Inc.
Developer-first voice agent platform with code-level control, custom LLM routing and a deep TypeScript SDK plus REST/webhook surface.
- Pricing from
- $0.05 per minute
- Founded
- 2023
- HQ
- San Francisco, CA
Feature matrix
| Feature | Retell AI | Vapi |
|---|---|---|
| Authoring | ||
| Builder experience | Visual flow + promptsNo-code friendly | Code-first SDKTypeScript + REST + webhooks |
| Performance | ||
| Latency (end-to-end) | ~700 ms medianBundled stack | ~600 ms medianTunable via custom LLM |
| Infrastructure | ||
| Telephony | Bundled (Twilio under the hood) | BYO (Twilio, Telnyx, SIP) |
| Model layer | ||
| LLM choice | GPT-4o / Claude (managed) | Any (OpenAI, Anthropic, Groq, custom) |
| Multilingual | ||
| Languages | ~20Hindi via ElevenLabs/Deepgram | 30+Depends on chosen TTS/STT |
| Operations | ||
| Built-in analytics | YesCalls, sentiment, outcomes | BasicShip to your data warehouse |
| RAG | ||
| Knowledge base | Built-in vector store | BYO (Pinecone, Weaviate, custom) |
Builder experience
- Retell AI
- Visual flow + promptsNo-code friendly
- Vapi
- Code-first SDKTypeScript + REST + webhooks
Latency (end-to-end)
- Retell AI
- ~700 ms medianBundled stack
- Vapi
- ~600 ms medianTunable via custom LLM
Telephony
- Retell AI
- Bundled (Twilio under the hood)
- Vapi
- BYO (Twilio, Telnyx, SIP)
LLM choice
- Retell AI
- GPT-4o / Claude (managed)
- Vapi
- Any (OpenAI, Anthropic, Groq, custom)
Languages
- Retell AI
- ~20Hindi via ElevenLabs/Deepgram
- Vapi
- 30+Depends on chosen TTS/STT
Built-in analytics
- Retell AI
- YesCalls, sentiment, outcomes
- Vapi
- BasicShip to your data warehouse
Knowledge base
- Retell AI
- Built-in vector store
- Vapi
- BYO (Pinecone, Weaviate, custom)
Pricing
Starter
Retell AI
$0.07/min + LLM/TTS pass-through
- Visual builder
- Bundled telephony
- Up to 5 agents
Free $10 trial credit
Vapi
$0.05/min + LLM/TTS pass-through
- SDK access
- BYO telephony
- Unlimited agents
Free $10 trial credit
Growth
Retell AI
From $499/mo + usage
- Team seats
- Concierge onboarding
- SLA email support
Vapi
Usage-only, no minimum
- Slack support
- Priority queue
- Higher rate limits
Enterprise
Retell AI
Custom
- SOC 2
- Single-tenant
- Custom voice
- Solutions team
Vapi
Custom
- VPC deploy
- Custom LLM hosting
- Dedicated infra
Pros & cons
Retell AI
Pros
- Fastest time-to-first-agent for non-engineers
- Bundled telephony + analytics out of the box
- Built-in RAG for support deflection use cases
- Strong English voice quality with ElevenLabs default
Cons
- Less control over LLM cost/routing
- Limited custom function-calling depth
- Higher per-minute cost than DIY stacks
- Indian-language quality lags Hindi-first vendors
Vapi
Pros
- Full code-level control of every turn
- Mix-and-match LLM/TTS/STT for cost or quality
- Strong webhook surface for CRM/CDP wiring
- Active developer community + docs
Cons
- Requires engineering bandwidth to ship
- No bundled telephony — you wire Twilio/Telnyx
- Analytics are bring-your-own
- Knowledge-base layer is BYO (Pinecone et al.)
Our verdict
Pick Vapi
For most production deployments with engineering bandwidth, Vapi wins on cost, latency and flexibility. Retell is the right pick if you need a no-code path to first live agent and don't care about LLM-routing economics. Teams in regulated markets (banking, healthcare, real estate) typically layer a managed partner like Kallix on top of either platform to handle compliance, multilingual quality and ongoing prompt tuning.
Scenario picks
Non-technical founder shipping a clinic receptionist in a week
→ Retell AI. Visual builder + bundled telephony beats wiring SDK + Twilio yourself.
Engineering team building a multilingual outbound dialer with custom CRM logic
→ Vapi. Code-level control and a custom LLM router give you the lowest cost-per-call.
Indian banking / NBFC outbound compliance in Hindi + 6 regional languages
→ Vapi. Pick the best Hindi STT (Sarvam/Deepgram) and Indian-accent TTS (Sarvam/ElevenLabs) per call.
Related questions
Vapi is typically 20-35% cheaper at scale because you control LLM and TTS choice (e.g. Groq + ElevenLabs Turbo) and bring your own telephony rates. Retell's bundled pricing is simpler but harder to optimise.
Vapi gives you better Hindi quality if you wire Sarvam AI or Bhashini under the hood. Retell ships acceptable Hindi via ElevenLabs but you can't swap the STT layer.
Both offer BAA and SOC 2 on enterprise plans. For India DPDP / RBI use cases, you'll likely need a managed implementation partner to handle data residency and consent flows.
Retell: 1–3 days for a non-engineer. Vapi: 1–2 weeks for an engineer to ship a polished agent with CRM integration and call analytics.
Citations
- Retell AI pricing pageRetell AI
- Vapi pricing pageVapi Labs
- Voice AI latency benchmarks 2026Kallix