Which is cheaper, Vapi or Retell?

Vapi, on every stack above the absolute floor. Vapi's own pricing calculator estimates $82 to $129 for a 1,000-minute month, which is $0.082 to $0.129 per minute all-in on its free telephony. Retell meters four lines separately rather than bundling them, so a comparable Retell stack of $0.055 voice infrastructure plus $0.015 text-to-speech plus a $0.064 per minute recommended model plus $0.015 telephony is $0.149 per minute, and a premium Retell stack is $0.270. The one place Retell wins is the cheapest possible configuration: $0.076 per minute with its own SIP trunk and the cheapest model, against Vapi's $0.082 floor. Neither vendor publishes a volume tier, so high-volume pricing is a quote from both.

Which has lower latency, Vapi or Retell?

Retell publishes 250 to 400ms first-token-to-first-audio for the standard inbound configuration. Vapi achieves comparable latency on optimised stacks but the default stack (ElevenLabs Turbo TTS) typically sits at 500 to 800ms. For sub-500ms reliably, Retell standard or Vapi with Cartesia Sonic TTS are the two best choices.

Which is easier to build with?

Retell is easier for prototyping because the bundled stack means fewer provider accounts and one billing line. Vapi is more flexible (BYOK for OpenAI, Anthropic, Google, plus custom telephony pipelines) but requires more provider relationships and billing complexity. For a first-time voice AI agent, Retell ships faster; for a sophisticated multi-model agent, Vapi gives more control.

Does Vapi or Retell support warm transfer to humans?

Both support warm transfer via SIP or REFER. Implementation patterns differ: Vapi exposes lower-level telephony controls and supports custom transfer logic; Retell provides higher-level abstractions that work for standard transfer flows but constrain edge cases. For complex transfer logic (transfer + context push to CRM + AE notification), Vapi has more headroom.

Which has better community and documentation?

Vapi has the larger developer community (active Discord, more YouTube tutorials, more third-party content). Retell's documentation is cleaner and more focused but the community is smaller. For learning resources Vapi has more depth; for in-product onboarding Retell has the smoother first-30-minutes experience.

Vapi vs Retell AI in 2026: The Honest Voice AI Comparison

Two of the most-deployed voice AI platforms in 2026. Vapi charges for hosting and passes the rest through at cost; Retell meters four lines and quotes a band across them. The right choice depends on whether you value per-minute cost and control, or latency and a single invoice. Here is the side-by-side that engineering procurement actually needs, built only from rates each vendor publishes.

Last verified June 2026; every rate re-read from vapi.ai/pricing and retellai.com/pricing on 23 September 2026.

The verdict on this page has reversed. Until September 2026 it concluded Retell was cheaper all-in, about 21 percent at the mid stack. That rested on a Vapi all-in figure of $0.25 to $0.33 a minute and on treating Retell's $0.07 as a bundle covering speech-to-text, text-to-speech and telephony. Neither survives a read of the two pricing pages. Vapi's own calculator puts an all-in minute at $0.082 to $0.129, and Retell prices four lines separately, putting a realistic sales stack at $0.149. On published rates Vapi is the cheaper platform on every configuration except the absolute floor. The correction is stated here rather than quietly absorbed into the tables below.

Vapi

Hosting plus at-cost pass-through

$0.05/min hosting

All-in on Vapi's own calculator: $0.082 to $0.129/min, with Vapi Telephony and SIP free.

+ Cheapest all-in on published rates above the floor
+ Models pass through at provider cost with no markup
+ Maximum component flexibility (BYOK supported widely)
+ Larger developer community + ecosystem
+ Free first-party telephony, SIP, WebSockets and Daily WebRTC
- Support is a separate Success Package ($29/mo Core, $999/mo Pro minimum)
- HIPAA handling is a $2,000/mo add-on; extra lines $10 each per month
- More moving parts to manage and debug

Retell AI

Four metered lines, one invoice

$0.07-$0.31/min band

Mid sales stack: $0.149/min. Budget $0.076 on your own SIP trunk; premium $0.270.

+ Best published latency (250-400ms inbound)
+ One invoice, one vendor relationship
+ Published add-on menu rather than quote-only extras
+ Free telephony if you bring your own SIP trunk
+ Cleaner first-30-minutes developer experience
- More expensive per minute than Vapi at mid and premium stacks
- No volume tiers published at all; scale pricing is a quote
- Smaller developer community + fewer tutorials

§All-In Per-Minute Cost: Real Stack Comparison

Stack tier	Vapi	Retell	Cheaper
Budget (cheapest model, free transport)	$0.082/min	$0.076/min	Retell by 7%
Mid (recommended model, carrier transport)	$0.119/min	$0.149/min	Vapi by 20%
Premium (top model + ElevenLabs voice)	$0.143/min	$0.270/min	Vapi by 47%
High volume (250K min/mo)	$0.082-$0.129/min at list	$0.149/min at list	Neither publishes a volume tier

The cost reading, re-derived: the two platforms cross over. At the absolute floor Retell is marginally cheaper, because its $0.055 voice infrastructure covers speech-to-text where Vapi charges $0.05 hosting plus $0.0095 for Deepgram, and both give you free transport if you bring your own trunk. The moment you pick a production model the order reverses and the gap widens: Retell's recommended-tier models are $0.064 to $0.16 a minute against the $0.0077 to $0.0452 Vapi passes through, so Vapi is 20 percent cheaper at mid and 47 percent cheaper at premium. Neither publishes a volume tier, so the high-volume row is list arithmetic rather than a quote, and both say enterprise pricing is custom. The practical read: if you are running the cheapest possible qualifier on your own SIP trunk, the platforms are within a fraction of a cent of each other and latency should decide it. If you are running a real sales agent on a real model, Vapi is materially cheaper.

§Latency Comparison: First-Token to First-Audio

Latency is the single most important quality dimension for outbound sales voice AI, because long pauses signal "robot" to prospects and elevate hang-up risk. Both Vapi and Retell publish latency benchmarks; here is the honest 2026 picture.

Configuration	Vapi	Retell
Inbound + standard TTS (ElevenLabs Turbo + GPT-4o-mini)	500-800ms	250-400ms
Inbound + Cartesia Sonic TTS (latency-optimised)	250-400ms	Not standard
Inbound + ElevenLabs Multilingual v2 (premium)	800-1200ms	500-800ms
Outbound (adds carrier dial-time)	+1-3s startup	+1-3s startup

The latency reading: Retell is faster than Vapi at standard configurations because the bundled stack lets Retell pre-warm and co-locate providers. Vapi catches up if you build a latency-optimised stack with Cartesia Sonic TTS, but most Vapi deployments default to ElevenLabs Turbo and run slower than Retell standard. For sub-500ms reliably, Retell standard is the path of least resistance.

§Build Complexity and Developer Experience

For the engineering team estimating build effort, the difference between Vapi and Retell is meaningful but not enormous. Both ship usable production agents in 2 to 6 weeks of work. The differences are in the corners.

Vapi build experience

+ Larger Discord community for debugging help
+ More open-source example agents on GitHub
+ Lower-level telephony controls for custom flows
+ BYOK supports almost any major LLM provider
- More provider accounts to manage (Deepgram + OpenAI + ElevenLabs + Twilio + Vapi)
- Billing reconciliation across 5 providers
- More edge cases to handle in production

Retell build experience

+ Single account, single bill, single dashboard
+ Cleaner default-paved-path; fewer decisions to make in week 1
+ Stronger Knowledge Base ingestion for RAG patterns
+ Higher-level transfer abstractions for standard cases
- BYOK constrained vs Vapi
- Smaller community = slower answers to obscure issues
- Less flexibility on custom telephony beyond Twilio/Telnyx

§The Decision Framework

Choose Vapi if

+ All-in per-minute cost is the deciding factor on a production model
+ You want model costs passed through at provider cost with no markup
+ You need maximum component flexibility (custom LLM, custom telephony)
+ Free first-party telephony matters more than a managed carrier route
+ Your team values open-source examples and large community
+ You are deploying multiple agents with different model preferences

Choose Retell if

+ Sub-500ms latency reliability is a hard requirement
+ You want a single bill, single dashboard, single provider
+ A published add-on menu beats negotiating extras (knowledge base, denoising, PII removal)
+ Support without a separate package fee matters
+ You are running the cheapest possible qualifier on your own SIP trunk, where Retell edges Vapi
+ Time-to-first-production-agent is the priority

§FAQ

Is Vapi or Retell better for outbound cold calling?

Both are technically capable. Both leave the TCPA compliance burden with the operator (FCC Ruling 24-17 requires prior express consent for AI outbound voice). On published rates Vapi wins on cost per call, at $0.082 to $0.129 a minute against a $0.149 mid Retell stack, and it also has more headroom for custom telephony pipelines with sophisticated retry and carrier routing. Retell's counterweights on outbound are latency and its published batch-call and branded-call add-ons. Bland remains the third option and the only one of the three with a dialer included.

Can I use the same LLM (GPT-4o, Claude Sonnet) on both platforms?

Yes. Both Vapi and Retell support major LLM providers including OpenAI (GPT-4o, GPT-4o-mini), Anthropic (Claude Sonnet 3.5, Haiku), Google (Gemini Pro, Flash), and several others. Vapi's BYOK is more flexible at the configuration level; Retell's default selection is curated for bundled pricing.

What about Bland AI as a third option?

Bland includes a built-in dialer and sequencer, which Vapi and Retell do not. For pure outbound sales use cases where you do not want to build dialer infrastructure, Bland is the third realistic option. On published rates it sits between the two: $0.14 a minute on the free Start tier and $0.12 on Build with a $299 a month platform fee, against Vapi at $0.082 to $0.129 and a mid Retell stack at $0.149. It is also the simplest of the three to forecast, because the rate is one all-in number per tier with no model pass-throughs. Bland withdrew its $499 a month Scale tier during 2026, so $0.12 is now its cheapest published rate.

Do both support knowledge base ingestion (RAG)?

Yes, both support knowledge-base ingestion for retrieval-augmented generation. Retell's KB integration is more polished out of the box (built-in chunking, automatic ingestion of PDFs and web pages, default retrieval up to 100MB). Vapi requires more configuration but supports custom retrieval pipelines if you bring your own vector store.

How do they handle multi-language outbound?

Both support multi-language deployments. The constraint is the underlying TTS voice provider. ElevenLabs Multilingual v2 supports 30+ languages but at the highest cost tier; Cartesia Sonic supports a smaller set at lower cost. For Spanish, French, German, and Portuguese, both Vapi and Retell deliver production-quality voices via ElevenLabs or PlayHT.

What is the TCPA risk on outbound for both?

Identical. Both platforms are infrastructure; the TCPA compliance burden sits with the operator regardless of platform choice. FCC Ruling 24-17 (February 2024) classifies AI-generated voice calls as artificial or prerecorded under TCPA, requiring prior express consent for outbound. Use the legal recording consent guide for full detail.

Vapi pricing →Retell pricing →Bland pricing →All voice AI compared →Build vs buy AI SDR →