Complete comparison of Vapi, Bland AI, and Retell AI for voice AI agents. Features, pricing, use cases, and which platform to choose for AI sales calls in 2025.
Vapi vs Bland AI vs Retell AI: Which AI Voice Agent is Best for Sales in 2025?
AI voice agents are transforming sales. Instead of human SDRs making cold calls, AI agents can now have natural conversations, qualify leads, and book meetings—24/7.
Three platforms dominate this space: Vapi, Bland AI, and Retell AI.
Each has different strengths. Here's how to choose.
The Quick Comparison
| Factor |
Vapi |
Bland AI |
Retell AI |
| Best For |
Developers, omnichannel |
Compliance-heavy industries |
Customer support, inbound |
| Approach |
API-first |
Security-focused |
Fully-featured platform |
| Ease of Use |
Technical |
Technical |
Moderate |
| Uptime |
99.94% |
99.94% |
99.99% |
| Pricing |
$0.05/min + usage |
$0.09/min connected |
$0.07/min flat |
| STT Included |
Extra cost |
Included |
Included |
| Best Voice Quality |
Very good |
Very good |
Very good |
TL;DR:
- Choose Vapi for developer flexibility and omnichannel deployment
- Choose Bland AI for regulated industries needing maximum security
- Choose Retell AI for the most complete out-of-box platform
Understanding Voice AI Agents
Voice AI agents aren't simple chatbots with text-to-speech. They're sophisticated systems that:
- Listen - Real-time speech recognition
- Understand - Natural language processing
- Think - LLM-powered reasoning
- Respond - Natural voice synthesis
- Act - Integration with CRMs, calendars, etc.
The best platforms handle this entire pipeline with minimal latency—so conversations feel natural.
Vapi: The Developer's Choice
Vapi is built for developers who want maximum control and customization.
Strengths
API-First Architecture
Everything is accessible via API. Build exactly what you need without platform limitations.
Omnichannel Support
Deploy the same voice agent across:
- Phone calls
- Web widgets
- Mobile apps
- Any voice-enabled platform
Model Flexibility
Use any LLM:
- OpenAI (GPT-4, GPT-4o)
- Anthropic (Claude)
- Custom/fine-tuned models
- Local LLMs
Function Calling
Your agent can execute actions mid-conversation:
- Check inventory
- Book appointments
- Update CRM records
- Process payments
Limitations
- Steeper learning curve
- Speech-to-text costs extra ($0.01/min)
- Requires development resources
- Less turnkey than alternatives
Pricing
| Component |
Cost |
| Platform |
$0.05/min |
| Speech-to-Text |
$0.01/min |
| Voice (varies) |
$0.01-0.03/min |
| LLM |
Pass-through |
Total typical cost: $0.08-0.12/min depending on configuration
Best For
- Developer teams building custom solutions
- Companies needing omnichannel voice AI
- Startups wanting maximum flexibility
- Integrations requiring custom logic
Bland AI: The Security-First Choice
Bland AI focuses on security and compliance—solving concerns that keep voice AI out of regulated industries.
Strengths
Enterprise Security
- SOC 2 Type II certified
- HIPAA compliant
- On-premise deployment options
- Data never leaves your control
Compliance Focus
Built for industries with strict requirements:
- Healthcare
- Financial services
- Legal
- Government
Custom Voice Cloning
Create branded voices that sound like your team—with proper consent workflows built in.
Pathway Designer
Visual conversation flow builder for non-developers to design call scripts.
Limitations
- Higher base price
- Less developer flexibility than Vapi
- Smaller integration ecosystem
- Outbound-focused (less inbound optimization)
Pricing
| Type |
Cost |
| Connected calls |
$0.09/min |
| Outbound attempts (<10s) |
$0.015 each |
| Enterprise |
Custom |
Total typical cost: $0.09/min for connected calls (all-inclusive)
Best For
- Regulated industries (healthcare, finance, legal)
- Enterprise companies with strict security requirements
- Organizations needing on-premise deployment
- Teams prioritizing compliance over customization
Retell AI: The Complete Platform
Retell AI offers the most polished, fully-featured platform for building voice agents.
Strengths
Highest Uptime
99.99% uptime SLA—higher than Vapi and Bland (99.94%). For mission-critical voice applications, this matters.
All-Inclusive Pricing
$0.07/min includes:
- Platform
- Speech-to-text
- Voice synthesis
- No hidden costs
Best Inbound Handling
Optimized for customer support:
- Call routing
- Queue management
- Transfer to humans
- Post-call summaries
Visual Builder + Code
Both no-code visual tools and API access. Best of both worlds.
Multi-Channel
- Phone (inbound/outbound)
- Web calling
- Native mobile SDKs
Limitations
- Less flexible than Vapi for custom architectures
- Fewer deployment options than Bland
- Smaller model selection
Pricing
| Plan |
Cost |
| Pay-as-you-go |
$0.07/min |
| Enterprise |
Custom |
Total typical cost: $0.07/min flat (everything included)
Best For
- Customer support automation
- Inbound call handling
- Teams wanting complete solution without development
- Companies prioritizing reliability over customization
Head-to-Head: Outbound Sales
The primary use case driving voice AI adoption: outbound sales calls.
Call Quality
All three platforms produce natural-sounding conversations. Differences are subtle:
- Vapi: Highly configurable voice parameters
- Bland AI: Strong voice cloning capabilities
- Retell AI: Consistent, polished default voices
Verdict: Near-equal. Voice quality is no longer a differentiator.
Latency
Conversation feel depends on response speed:
- Vapi: Very fast with optimized configuration
- Bland AI: Fast, optimized for natural turn-taking
- Retell AI: Consistently fast out of box
Verdict: All three achieve sub-second latency. Retell is most consistent without tuning.
Integration with Sales Tools
How easily do they connect to your stack?
Vapi:
- Any CRM via API
- Webhooks for real-time events
- Requires custom integration work
Bland AI:
- Native HubSpot, Salesforce integrations
- Pathway designer with CRM actions
- Enterprise connectors available
Retell AI:
- Growing native integration list
- Webhook-based for custom
- API for anything else
Verdict: Bland AI has slight edge for enterprise CRM. All three integrate with everything via API.
Head-to-Head: Pricing for Scale
At scale, pricing differences matter. Let's compare 10,000 minutes/month.
Vapi
Platform: $0.05 × 10,000 = $500
STT: $0.01 × 10,000 = $100
Voice: ~$0.02 × 10,000 = $200
LLM: ~$150 (varies)
Total: ~$950/month
Bland AI
Connected: $0.09 × 10,000 = $900
Failed attempts: ~$100
Total: ~$1,000/month
Retell AI
Flat rate: $0.07 × 10,000 = $700
Total: $700/month
Verdict: Retell AI is cheapest at scale. Vapi and Bland are similar.
Head-to-Head: Development Experience
Vapi
// Vapi - Maximum flexibility
const assistant = await vapi.createAssistant({
model: {
provider: "anthropic",
model: "claude-3-opus",
temperature: 0.7
},
voice: {
provider: "elevenlabs",
voiceId: "custom-voice-id"
},
functions: [
{
name: "bookMeeting",
// ... custom function
}
]
});
Developer experience: Excellent. Full control over every component.
Bland AI
// Bland AI - Guided but powerful
const call = await bland.calls.create({
phone_number: "+1234567890",
pathway_id: "sales-qualification",
voice: "custom-clone",
transfer_number: "+1987654321"
});
Developer experience: Good. Pathway system adds structure.
Retell AI
// Retell AI - Balanced approach
const agent = await retell.createAgent({
voice_id: "eleven-labs-voice",
llm_model: "gpt-4",
general_prompt: "You are a sales representative..."
});
Developer experience: Good. Less configuration, faster to start.
Verdict: Vapi for maximum control. Retell for fastest implementation. Bland in between.
When to Choose Each Platform
Choose Vapi If:
- You have developers who can build custom integrations
- You need omnichannel (phone + web + mobile)
- You want model flexibility (bring your own LLM)
- You're building a product on top of voice AI
- Customization matters more than turnkey simplicity
Choose Bland AI If:
- You're in a regulated industry (healthcare, finance, legal)
- Security is paramount (SOC 2, HIPAA required)
- You need on-premise deployment options
- You want custom voice cloning with compliance
- Enterprise contracts are required
Choose Retell AI If:
- You want the complete package without piecing together components
- Reliability is critical (99.99% uptime SLA)
- You're focused on inbound customer support
- Budget matters at scale (lowest per-minute)
- You want fast deployment without deep technical work
Common Voice AI Use Cases
AI SDR (Outbound Sales)
Best platform: Any of the three
All handle outbound sales well. Choose based on:
- Vapi if building custom sales AI product
- Bland AI if in regulated industry
- Retell AI if optimizing for cost
AI Receptionist (Inbound)
Best platform: Retell AI
Retell's inbound optimization, call routing, and reliability make it ideal for handling incoming calls.
Lead Qualification
Best platform: Vapi or Retell AI
Both offer strong function calling for qualifying leads mid-call and syncing to CRM.
Appointment Setting
Best platform: Any (all integrate with calendaring)
Core use case for all three. Differences are marginal.
Customer Support
Best platform: Retell AI
Built-in features for support: queue management, transfers, escalation paths.
Migration Considerations
Switching between platforms isn't trivial. Consider:
- Voice consistency - Custom voices may not transfer
- Integration work - APIs differ, some rebuilding needed
- Phone numbers - May or may not be portable
- Conversation logs - Export before switching
Recommendation: Start with the right platform. Migrating is expensive.
Frequently Asked Questions
Which AI voice platform has the best call quality?
All three platforms—Vapi, Bland AI, and Retell AI—produce natural-sounding voice conversations. The differences in voice quality are now minimal. Your choice should be based on features, pricing, and use case rather than voice quality alone.
Is Vapi cheaper than Retell AI?
No, Retell AI is typically cheaper at scale. Vapi charges separately for platform ($0.05/min), speech-to-text ($0.01/min), and voice synthesis, totaling around $0.08-0.12/min. Retell AI charges a flat $0.07/min all-inclusive. At 10,000 minutes/month, Retell saves about $250.
Which platform is best for regulated industries?
Bland AI is purpose-built for regulated industries with SOC 2 Type II certification, HIPAA compliance, and on-premise deployment options. If you're in healthcare, finance, or legal, Bland AI addresses compliance requirements that other platforms may not.
Can I use my own AI model with these platforms?
Vapi offers the most flexibility—you can use OpenAI, Anthropic, custom fine-tuned models, or local LLMs. Bland AI and Retell AI offer model selection but with more limited options. If model choice is critical, choose Vapi.
Which platform is easiest to set up?
Retell AI is the most turnkey solution with the fastest path to deployment. Vapi requires more development work but offers more control. Bland AI falls in between with its visual Pathway Designer for non-developers.
What's the typical latency for AI voice calls?
All three platforms achieve sub-second response times, making conversations feel natural. Retell AI is most consistent out of the box. Vapi requires configuration to optimize latency. Real-world latency depends on your LLM choice and integration complexity.
The Bottom Line
The voice AI space is maturing fast. All three platforms can power effective AI sales agents.
Choose Vapi for developer flexibility and omnichannel needs.
Choose Bland AI for security-critical, regulated environments.
Choose Retell AI for the best complete platform at the lowest cost.
For most businesses starting with voice AI sales, Retell AI offers the best balance of features, reliability, and pricing.
For enterprises with compliance requirements, Bland AI is worth the premium.
For technical teams building custom solutions, Vapi provides unmatched flexibility.
The future of sales is voice AI. The question is which platform gets you there.
Implementing AI voice agents for your sales team? Cedar Operations helps businesses evaluate, implement, and optimize AI sales tools. Let's discuss your voice AI strategy →
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