Key Takeaways
- Vapi is the most developer-flexible platform of the three, supporting any combination of LLM provider (OpenAI, Anthropic, Google, custom endpoints) and voice provider (ElevenLabs, Azure, custom). The platform fee starts at $0.05 per minute, but total all-in cost including speech-to-text, LLM, and telephony typically runs $0.07 to $0.25 or more per minute depending on the stack you choose.
- Bland AI raised a $50 million Series C led by Dell Technologies Capital in June 2026, pushing total funding past $100 million. It has handled over 175 million AI phone calls and serves 250+ enterprise customers. Its base plan starts at $299 per month plus $0.09 per connected minute.
- Retell AI offers the lowest base price ($0.07 per minute, no mandatory platform fee), the lowest out-of-the-box latency (approximately 600 ms), and includes SOC 2 and HIPAA compliance on standard paid plans without a separate enterprise add-on. At 40,000 minutes per month, the all-in cost is approximately $2,800.
- At 40,000 minutes per month (10,000 calls of 4 minutes each), Retell invoices approximately $2,800 all-in, Bland runs $3,600 to $4,400, and Vapi scales to $7,200 to $8,800 once you add Deepgram, GPT-4o-mini Realtime, ElevenLabs Flash, and Twilio.
- Latency benchmark at default configuration: Retell at approximately 600 ms, Vapi at approximately 800 ms (tunable to 500 to 700 ms with Deepgram Nova-3 plus GPT-4o-mini), Bland at approximately 900 ms depending on Pathway complexity.
- Bland is strongest for high-volume outbound calling campaigns with its proprietary Bland Turbo voice model and internal LLM tuned for short, persuasive outbound conversations. Retell is strongest for inbound voice quality and cost efficiency at scale. Vapi is strongest for custom builds requiring explicit control over the full AI stack.
- Bland AI develops its own voice models in-house rather than building on top of third-party foundation models, which differentiates its voice quality approach from Vapi and Retell.
- HIPAA compliance: Retell and Bland include BAAs on standard paid plans. Vapi requires an Enterprise contract for HIPAA, typically with an add-on around $1,000 per month.
AI voice agents went from prototype technology to production infrastructure in 2024 and 2025. By 2026, the question is no longer whether to build voice agents but which platform to build them on. Vapi, Bland AI, and Retell are the three developer-focused platforms handling the most volume, and they have diverged significantly in architecture, pricing, and target use case over the past eighteen months.
The choice between them is not primarily about which has more features, but about what your call volume looks like, whether you need inbound or outbound or both, how much technical control you want over the AI stack, and what compliance requirements apply to your industry. This comparison covers the key differentiators and the cost math at real production volumes.
Quick Comparison: Vapi vs Bland AI vs Retell
| Feature | Vapi | Bland AI | Retell AI |
|---|---|---|---|
| Base price | $0.05/min platform fee | $299/month + $0.09/min | $0.07/min, no platform fee |
| All-in at 40K minutes/month | $7,200 to $8,800/month | $3,600 to $4,400/month | ~$2,800/month |
| Default latency | ~800 ms | ~900 ms | ~600 ms |
| Voice model | Third-party (ElevenLabs, Azure, etc.) | Proprietary Bland Turbo | Third-party (configurable) |
| LLM model | Any: OpenAI, Anthropic, Google, custom | Proprietary + third-party options | GPT-5.x, Claude 4.5/4.6, others |
| HIPAA compliance | Enterprise only (~$1K/month add-on) | Standard paid plans | Standard paid plans |
| Best use case | Custom builds, full stack control | High-volume outbound campaigns | Inbound, cost efficiency at scale |
| Total funding | Not disclosed | $100M+ (June 2026) | Not disclosed |
What is Vapi?
Vapi is a developer platform for building, testing, and deploying voice AI agents. It functions as an orchestration layer that lets developers compose a voice agent from the best components across the AI ecosystem: any LLM from OpenAI, Anthropic, Google, or a custom endpoint; any voice synthesis from ElevenLabs, Azure, or custom providers; and any telephony integration they choose. Vapi’s core value proposition is that developers retain explicit control over every component of the stack rather than being locked into a single vendor’s model choices.
The platform supports structured outputs, tool calls, fallback behavior configuration, and custom LLM endpoints, which makes it the strongest choice for teams building voice agents with non-standard requirements. A healthcare team that needs a specific compliant LLM, a fintech team that needs a particular low-latency voice model, or a developer who wants to test multiple model combinations against each other can configure all of that within Vapi in ways the other platforms do not support.
The pricing structure reflects this flexibility. The platform fee starts at $0.05 per minute, but that is only the orchestration layer. The full cost adds speech-to-text at the provider’s rate, LLM inference at the model’s token rate, text-to-speech at the voice provider’s rate, and telephony charges. At production volumes, Vapi’s total cost per minute typically runs $0.07 to $0.25 or more, making cost predictability harder than with Bland or Retell’s flatter structures. Enterprise pricing is custom and typically runs $40,000 to $70,000 per year for platform access alone.
What is Bland AI?
Bland AI is a voice AI platform built for automated phone agents at enterprise scale, focused specifically on regulated industries where call quality and reliability matter more than price per minute. Founded in San Francisco in 2023 and led by CEO Isaiah Granet, Bland raised a $50 million Series C in June 2026 led by Dell Technologies Capital, with participation from HubSpot Ventures, Archerman Capital, and Tribeca Venture Partners. Total funding exceeds $100 million. The company has handled over 175 million AI phone calls and serves 250+ enterprise customers including Samsara, Kin Insurance, and CNO Financial Group.
The technical differentiator from Vapi and Retell is Bland’s proprietary model stack. While both competitors primarily route through third-party models like GPT-4o or Claude, Bland develops its own speech models in-house, purpose-built for voice. The Bland Turbo voice model is tuned for short, persuasive outbound conversations rather than general-purpose dialogue. Bland also maintains a proprietary LLM tuned specifically for phone call scenarios, which produces different response patterns than a general-purpose model would.
Bland’s Pathways feature lets teams design visual call flows where the agent follows different branches depending on how the conversation progresses, with condition-based routing between nodes. This is particularly useful for outbound campaigns where the call structure is predictable but the responses vary. SIP integration supports existing enterprise telephony infrastructure without requiring a full telephony migration. Pricing starts at $299 per month plus $0.09 per connected minute, with enterprise pricing fully custom. BAAs for HIPAA are available on standard paid plans.
What is Retell AI?
Retell AI is a voice agent platform that positions itself on the combination of lowest latency, best inbound voice quality, and lowest total cost at scale. The pricing model starts at $0.07 per minute with no mandatory platform fee, and includes $10 in free credits (approximately 60 minutes) to start. SOC 2 and HIPAA compliance are included on standard paid plans, as are business associate agreements, without requiring an enterprise contract or a separate add-on purchase.
At default configuration, Retell’s out-of-the-box latency is approximately 600 ms, which is below the 800 ms threshold where callers generally stop noticing AI processing delay in routine conversation flow. This makes it the platform of choice for inbound customer service applications where natural conversational pacing is the primary quality metric. Retell’s modular billing model charges separately for voice infrastructure at $0.055 per minute, LLM agent costs from $0.006 per minute for basic models to $0.06 per minute for advanced options, and telephony at $2 per month per phone number plus $8 per month per concurrent call beyond the 20 included.
Retell supports current-generation models including GPT-5.x variants (5 nano through 5.5) and Claude 4.5 and 4.6 Sonnet, which were not available in prior platform pricing structures. At enterprise volumes, pricing can scale down to approximately $0.05 per minute. The all-in cost at 40,000 minutes per month is approximately $2,800, which is materially lower than both competitors at the same volume.
Vapi vs Bland AI vs Retell: Feature-by-Feature Breakdown
Latency and Voice Quality
Retell holds the latency advantage at approximately 600 ms out of the box, below the perceptible delay threshold for most callers in standard conversation. Vapi can be tuned to 500 to 700 ms median latency with an optimized stack (Deepgram Nova-3 plus GPT-4o-mini plus ElevenLabs Flash) but requires deliberate configuration to reach that range; the default is approximately 800 ms. Bland sits at approximately 900 ms depending on Pathway complexity, as the visual call flow branching adds processing overhead relative to simpler architectures.
On voice quality, Bland’s proprietary Turbo model is specifically tuned for outbound persuasion, producing speech that independent testers describe as better suited to sales calls than the general-purpose voice models on the other platforms. Retell delivers the most natural-sounding inbound conversational voice on standard telephony. Vapi’s voice quality depends entirely on which provider the developer configures, making it best for teams with a specific voice requirement rather than teams using the platform default.
Pricing at Scale
The pricing comparison changes significantly between headline rates and actual all-in costs at production volume. At 10,000 calls of 4 minutes each (40,000 minutes per month), Retell invoices approximately $2,800 all-in. Bland on the Scale plan runs $3,600 to $4,400. Vapi’s $0.05 per minute platform fee becomes $7,200 to $8,800 per month once Deepgram, GPT-4o-mini Realtime, ElevenLabs Flash, and Twilio are factored in.
This makes Vapi’s headline rate the least meaningful of the three for budgeting. Teams evaluating Vapi should model their specific component stack before projecting monthly cost. Teams choosing Retell or Bland get more predictable pricing, with Retell’s modular structure making it easier to optimize individual cost components without switching platforms.
Compliance and Security
Retell and Bland both include HIPAA compliance and business associate agreements on standard paid plans. For healthcare, insurance, or financial services teams where HIPAA is a baseline requirement, both are viable without an enterprise contract. Vapi requires an Enterprise contract for HIPAA compliance, typically with an add-on charge around $1,000 per month, which represents a meaningful additional cost for compliance-required industries at smaller scales.
Retell includes SOC 2 on standard plans as well, giving it the strongest compliance offering for teams that need both certifications at entry pricing.
Flexibility and Customization
Vapi leads on technical flexibility by a significant margin. The ability to specify any LLM provider and endpoint, configure structured outputs, define tool calls and fallback behavior, and swap any component of the AI stack independently is the primary reason developers choose Vapi over the alternatives. Teams building voice agents with non-standard model requirements, custom speech-to-text pipelines, or experimental LLM configurations will find Vapi the only viable option among the three.
Bland’s visual Pathways builder offers a different kind of customization: designing call flows graphically without requiring code for each branch condition. This is powerful for sales and outreach teams that know their call structure but do not have engineering resources to script every branching path programmatically. Retell sits between the two, offering configurable model choices and call flow design without Vapi’s full provider flexibility or Bland’s visual flow builder.
Who Should Use Which?
Retell is the default recommendation for teams starting their first production voice agent deployment, particularly for inbound customer service. The combination of lowest latency, included HIPAA compliance, and lowest all-in cost at scale makes it the most practical starting point for most businesses. Teams in regulated industries that need a BAA without negotiating an enterprise contract will find Retell’s standard compliance posture the fastest path to production.
Bland AI is the best fit for enterprises running high-volume outbound calling campaigns, particularly in regulated industries. The proprietary voice model, the Pathways visual call flow builder, and the company’s track record across 175 million calls give enterprise buyers confidence in its reliability at scale. The $50 million Series C and 250+ enterprise customer base make it the most credible enterprise vendor of the three for procurement teams evaluating vendor stability.
Vapi is the right choice for teams that have specific technical requirements that neither Bland nor Retell can satisfy: a particular LLM provider, a custom speech-to-text model, experimental stack configurations, or integration with a proprietary telephony system. Developer teams building voice agents as a product rather than deploying them internally will often choose Vapi for the control it provides over what gets shipped to end users.
Verdict
For most teams, Retell offers the strongest combination of price, latency, compliance, and simplicity at production scale. Bland is the better choice for outbound-heavy enterprise deployments where voice quality and campaign structure matter more than cost per minute. Vapi wins for developers who need to control every layer of the stack and are willing to invest in configuration and cost monitoring to maintain that control.
The AI voice agent space is moving fast. Bland’s $50 million raise in June 2026 signals continued investment in proprietary models, and Retell’s current-generation model support (GPT-5.x, Claude 4.6) shows active platform development. Teams choosing a platform today should evaluate not just current pricing and features but which vendor’s investment trajectory aligns with where their voice agent requirements will be in 12 to 18 months.
Frequently Asked Questions
What is the cheapest AI voice agent platform between Vapi, Bland, and Retell?
Retell is the cheapest at scale with an all-in cost of approximately $2,800 per month at 40,000 minutes of calls. Bland runs $3,600 to $4,400 at the same volume. Vapi’s headline $0.05 per minute grows to $7,200 to $8,800 per month at scale once speech-to-text, LLM, voice synthesis, and telephony costs are added. Retell also has no mandatory platform fee, making it the lowest barrier to entry for new deployments.
Which platform has the lowest latency?
Retell AI leads with approximately 600 ms latency out of the box at default configuration. Vapi can be tuned to 500 to 700 ms with an optimized component stack but averages approximately 800 ms at default. Bland AI averages approximately 900 ms depending on Pathway complexity. All figures vary based on model choices, infrastructure region, and call complexity.
Does Vapi support HIPAA compliance?
Vapi supports HIPAA compliance on Enterprise plans only, typically with an add-on charge of approximately $1,000 per month. Retell and Bland both include HIPAA compliance and BAAs on standard paid plans without requiring an enterprise contract upgrade.
What is Bland AI’s Pathways feature?
Pathways is Bland AI’s visual call flow builder. It allows teams to design the structure of a phone conversation graphically, defining branches based on what the caller says or does. A sales call might branch differently if a prospect says they are interested versus not interested versus asks about pricing. Pathways makes this kind of conditional call design accessible without scripting each branch in code, which is particularly useful for non-technical sales and marketing teams building outbound campaigns.
What happened with Bland AI’s funding in 2026?
Bland AI raised a $50 million Series C in June 2026, led by Dell Technologies Capital. Additional investors included HubSpot Ventures, Archerman Capital, Tribeca Venture Partners, and all existing investors. The round pushed Bland’s total funding past $100 million and was positioned around expanding voice AI for complex, high-stakes enterprise conversations. The company was founded in 2023 and has handled over 175 million AI phone calls to date.
Which platform is best for inbound customer service calls?
Retell AI is the strongest choice for inbound customer service. Its approximately 600 ms default latency produces the most natural-sounding conversations, and its pricing makes it the most cost-efficient for inbound call volumes that can be unpredictable month to month. The included SOC 2 and HIPAA compliance also removes a common barrier for customer service deployments in regulated industries.
Can Vapi work with any LLM?
Vapi supports any LLM provider through its flexible configuration, including OpenAI, Anthropic, Google, and custom endpoints. This makes it unique among the three platforms. Retell supports a curated list of current-generation models including GPT-5.x and Claude 4.5 and 4.6. Bland uses a combination of its proprietary in-house LLM and third-party model options, but does not support arbitrary custom endpoints the way Vapi does.
How does Bland AI’s proprietary voice model differ from competitors?
Bland developed Bland Turbo in-house specifically for phone call scenarios rather than licensing a general-purpose voice synthesis model from a third-party provider. The model is tuned for short, persuasive conversational speech patterns common in outbound sales and outreach calls. This produces different voice characteristics from what ElevenLabs, Azure, or other third-party providers offer, particularly on short-form responses with assertive intonation. Both Vapi and Retell rely on third-party voice providers rather than proprietary in-house models.
