Vapi vs Retell vs Bland AI vs ElevenLabs: Voice AI Platforms Compared

The voice AI platform market consolidated fast. If you are building a production phone agent in 2026, four platforms account for nearly all serious deployments: Vapi, Retell AI, Bland AI, and ElevenLabs.

This is not a review of consumer AI assistants or end-to-end SaaS products. It is a comparison of the platforms you build on top of: the infrastructure layer for phone agents that answer calls, conduct conversations, book appointments, qualify leads, and handle intake.

Silverthread Labs builds on all four. Platform selection is part of our engagement process, and we have a fairly clear view of what each one is actually good for. Here is that view.

the four platforms at a glance#

Vapi: maximum flexibility, maximum overhead#

Vapi is a voice AI orchestration layer. It does not own speech-to-text, LLM inference, or text-to-speech: it lets you choose your own providers for each component and wires them together. You pick your STT (Deepgram, Gladia, others), your LLM (OpenAI, Anthropic, Groq, local models), and your TTS voice (ElevenLabs, PlayHT, OpenAI TTS, others). Vapi handles the real time audio pipeline, turn-taking logic, and session management between them.

This architecture gives developers more control than any other platform in this comparison. It is also where the problems start.

pricing: the real number, not the $0.05/min headline#

Vapi's headline rate is $0.05/minute for orchestration. That number is real: it is what Vapi itself charges. The total bill is not.

Real all-in cost (Lindy / Ringg.ai, 2026):

• Vapi orchestration: $0.05/min
• STT (Deepgram): ~$0.01/min
• LLM (GPT-4o at mid-volume): $0.02-$0.20/min depending on context length
• TTS (ElevenLabs): ~$0.04/min
• Telephony (Twilio): ~$0.01/min

Realistic all-in: $0.15-$0.36/min depending on LLM choice and call complexity. A call-intensive deployment at 10,000 minutes/month hits $1,500-$3,600 in infrastructure costs before any build or support fees.

HIPAA compliance is a dedicated add-on at $1,000/month. Without it, you cannot process ePHI through Vapi's infrastructure.

what Vapi is actually good for#

The flexibility is real. You can swap any component without rebuilding the pipeline. If a cheaper STT provider launches next month, you update a configuration line. If you have a fine-tuned model you want to route calls through, Vapi can do that. Multi-agent handoffs, real time interruption handling, architecturally unusual setups: Vapi handles these cases better than any alternative here.

Where it falls short is cost predictability and regulated-industry deployments. The component-level billing requires careful modeling, and projects that start on a rough estimate regularly end up with higher bills than expected. For healthcare or dental, paying $1,000/month on top of your per-minute costs just to get a BAA is hard to justify when Retell AI includes it for free.

Vapi is the right choice when your team has engineering bandwidth, you need component-level control, and you are not in a regulated industry.

Retell AI: the default for most production inbound#

Retell AI is a managed voice agent platform. Where Vapi gives you a component menu, Retell gives you a tested stack: speech processing, LLM routing, TTS, and telephony, with a no-code visual builder on top.

For most teams building inbound phone agents, this is the platform we reach for first. The reason is not just that it is simpler. It is that the all-in pricing is transparent and the compliance story is clean.

pricing: what you see is what you pay#

Retell's pricing (Retell AI, 2026):

Pay-as-you-go (no monthly plan): $0.07/min starting rate.

These are all-in rates: STT, LLM, TTS, and telephony included. The number on the pricing page is the number on the invoice. That alone is a significant advantage over Vapi.

HIPAA, SOC 2, and compliance without the premium#

HIPAA compliance with a Business Associate Agreement is included in standard pay-as-you-go pricing. No add-on, no separate compliance contract. The platform is also SOC 2 Type 1 and Type 2 certified.

For healthcare, dental, legal, and insurance deployments, the math is simple: Retell's compliance costs $0/month extra. Vapi's costs $1,000/month extra. At 2,000 minutes/month of inbound calls, Retell is often $800-$1,000/month cheaper than a HIPAA-enabled Vapi deployment. That gap is hard to argue against.

The one area where Retell gives ground is component flexibility. You work within Retell's curated stack. If you need a specific LLM or voice not in their catalog, you have fewer options than with Vapi. At very high volumes, you will also need an enterprise contract to get past the published tier limits.

Bland AI: built for volume#

Bland AI is a different kind of platform, and the numbers make that clear: 20,000+ concurrent calls per hour (Bland AI, 2026). No other platform here comes close to that.

Bland owns its infrastructure end to end: transcription, LLM inference, TTS, and telephony. That is how it achieves the capacity it does. The tradeoff is that you are working with a closed stack.

pricing#

• Base rate: $0.09/connected minute (Bland AI billing docs, 2026)
• Minimum per outbound call attempt: $0.015 per call regardless of answer status
• Premium voices: higher rates for premium voice options

For high-volume outbound at scale, Bland's per-minute rate is competitive with Retell's and lower than Vapi's realistic all-in cost.

what Bland is actually good for#

Outbound campaigns. Sales sequences, appointment reminder blasts, survey calls, collections outreach. If your use case is fundamentally about moving through a large list of numbers, Bland is purpose-built for that in a way the other platforms are not.

Owning the full stack also means Bland controls its own latency. End to end latency runs around ~500ms, faster than both Vapi and Retell. There are no third-party dependencies introducing variability.

What it does not do well: complex inbound conversation design. Nuanced inbound work, where the caller's needs drive a branching, adaptive dialogue, is harder to build on Bland's call graph model than on Retell or Vapi. The compliance tooling is also thinner. HIPAA is available in standard plans, but if you have complex regulated-industry requirements, the documentation and tooling depth is not what Retell provides. Evaluate carefully before committing.

ElevenLabs: the voice quality leader, not a phone platform#

ElevenLabs is primarily a voice generation platform: text-to-speech, speech-to-speech, and voice cloning at production quality. Conversational AI 2.0 adds agent capabilities: turn-taking, interruption handling, batch calling, and multilingual detection.

The platform delivers sub-300ms streaming latency and access to 11,000+ voices across 70+ languages (ElevenLabs pricing and product pages, 2026). On voice quality, it is the clear leader in this comparison. Nothing else is close.

pricing: credit-based at ~$0.08/min#

ElevenLabs Business plan includes 13,750 Conversational AI minutes at approximately $0.08/min all-in. One of the more transparent pricing structures in this comparison.

the core limitation#

ElevenLabs is not a phone platform. It does not natively handle PSTN calls, manage SIP trunking, or provide telephony infrastructure. To run it on actual phone calls, you need a separate telephony layer: Twilio, Vonage, or a SIP provider. That adds integration complexity and cost.

For consumer apps, web-embedded voice interfaces, gaming, kiosk experiences: none of that matters. For business phone agent deployments, it is a real architectural constraint that the other three platforms do not have.

If the voice is the product: a brand-voice experience, a lifelike consumer interaction, a gaming character. ElevenLabs is in a different class. The multilingual support (70+ languages, automatic detection) also makes it the right call for multilingual deployments. Just know what it is not.

feature-by-feature breakdown#

All pricing data as of March 2026. Rates subject to change: verify at each platform's current pricing page.

how to choose#

Our actual default, based on the deployments we have run: start with Retell AI unless there is a specific reason not to. The all-in pricing, the compliance story, and the no-code builder cover the majority of production inbound use cases cleanly. The reasons to look elsewhere are specific:

Go to Vapi when you need component-level control. Fine-tuned models, unusual LLM providers, architecturally non-standard pipelines. You need engineering bandwidth to run it well and you should model costs carefully before committing. Do not use it for healthcare or dental unless you are prepared to absorb the $1,000/month HIPAA add-on.

Go to Bland AI when volume is the primary variable. 20,000+ concurrent calls per hour is a category by itself. For appointment reminder blasts, sales sequences, or survey campaigns, Bland is purpose-built and nothing else here matches it. Do not use it for complex inbound flows or compliance-heavy regulated-industry work where the tooling depth matters.

Go to ElevenLabs when the voice itself is the differentiator and the interaction is not on a phone call. Consumer apps, gaming, kiosks, voice-first web experiences. Best latency for non-telephony interfaces, best voice quality in the comparison.

Use a combination when the requirements split. A healthcare practice typically needs Retell AI for inbound patient calls and Bland AI for outbound reminder campaigns. A sales organization might need Vapi's LLM flexibility for complex discovery conversations and ElevenLabs voice quality for brand-sensitive outbound touches. The architecture should follow the use case.

Not sure which platform fits your situation? A free automation audit covers your call workflow, compliance requirements, and volume profile, and gives you a specific recommendation with rationale.

FAQ#

What is the cheapest voice AI platform? Vapi looks cheapest at $0.05/min advertised, but real all-in costs reach $0.15-$0.36/min once you add STT, LLM, TTS, and telephony. ElevenLabs charges $0.08/min all-in. Retell AI starts at $0.07/min pay-as-you-go with no hidden component costs. Bland AI starts at $0.09/connected minute. For transparency on what you actually pay, Retell and ElevenLabs are easier to budget against.

Which voice AI platform is HIPAA-compliant? Retell AI includes a HIPAA BAA in standard pricing. Bland AI offers HIPAA compliance in standard plans. Vapi requires a $1,000/month add-on. ElevenLabs is not designed for telephony compliance workflows.

Is ElevenLabs a full voice agent platform? It has agent capabilities through Conversational AI 2.0, but it is not telephony-native. Running it on actual phone calls requires a separate telephony layer (Twilio, SIP trunking, or similar). It is the strongest choice for non-telephony voice interfaces: consumer apps, kiosks, gaming, and web-based voice.

How does Vapi compare to Retell AI? Vapi lets you choose your own LLM, STT, and TTS providers. Maximum control, but higher complexity, variable costs, and no visual builder. Retell AI has a managed stack, transparent plan pricing, a no-code builder, and HIPAA built in. Retell is faster to production for most teams. Vapi is the right call when you need to swap components or build something non-standard.

What is Bland AI best for? High-volume outbound: sales campaigns, appointment reminders, collections, surveys. It handles 20,000+ concurrent calls per hour. Not the right choice for complex inbound conversation design or compliance-heavy deployments.