OpenCall.ai vs Retell.ai Comparison (2025)
OpenCall.ai
Starting at $0.10/ minute
OpenCall doesn’t just pick up the phone and recite a script. It listens. It understands. And most impressively, it responds like a human would—fluidly, naturally, and with purpose. I’ve heard AI agents handle insurance verification calls, navigate complex scheduling workflows, and even wait patiently on hold before transferring the call back to a medical office at exactly the right moment. This isn’t voice automation; it’s delegation.
What makes OpenCall different is how deeply it integrates into a business’s backend systems. This means it can actually do things: check calendars, update patient records, confirm appointments, and triage urgent service requests—all without a human ever lifting the receiver. It’s not just about saving time (though it does, dramatically); it’s about transforming the customer experience into something responsive, seamless, and available 24/7.
What makes OpenCall different is how deeply it integrates into a business’s backend systems. This means it can actually do things: check calendars, update patient records, confirm appointments, and triage urgent service requests—all without a human ever lifting the receiver. It’s not just about saving time (though it does, dramatically); it’s about transforming the customer experience into something responsive, seamless, and available 24/7.
Key Metrics
Latency
700 ms
Automation
76%
Integrations
2000
Onboarding
2 days
OpenCall.ai
Score
93
Latency
700 ms
Automation
76%
Integrations
2000
Onboarding
2 days
Cost
Low
HIPAA Compliant
Yes
Retell.ai
Score
82
Latency
950 ms
Automation
55%
Integrations
25
Onboarding
1 days
Cost
Low
HIPAA Compliant
Yes
OpenCall.ai
OpenCall doesn’t just pick up the phone and recite a script. It listens. It understands. And most impressively, it responds like a human would—fluidly, naturally, and with purpose. I’ve heard AI agents handle insurance verification calls, navigate complex scheduling workflows, and even wait patiently on hold before transferring the call back to a medical office at exactly the right moment. This isn’t voice automation; it’s delegation.
What makes OpenCall different is how deeply it integrates into a business’s backend systems. This means it can actually do things: check calendars, update patient records, confirm appointments, and triage urgent service requests—all without a human ever lifting the receiver. It’s not just about saving time (though it does, dramatically); it’s about transforming the customer experience into something responsive, seamless, and available 24/7.
What makes OpenCall different is how deeply it integrates into a business’s backend systems. This means it can actually do things: check calendars, update patient records, confirm appointments, and triage urgent service requests—all without a human ever lifting the receiver. It’s not just about saving time (though it does, dramatically); it’s about transforming the customer experience into something responsive, seamless, and available 24/7.
Retell.ai
Retell AI offers fast, scalable voice agents with response times under a second and impressive developer flexibility. You can bring your own LLM, customize behavior deeply, and monitor everything through real-time dashboards. It’s well-suited for teams with in-house engineering that want control and scale. But the learning curve is real—getting up and running takes work, integrations often require custom scripts, and pricing isn’t transparent. While it performs well under the hood, Retell isn’t the most approachable platform for teams seeking simplicity or industry-ready templates out of the box.
Full Comparison
| Vendor | Score | Latency | Automation | Integrations | Cost | Action |
|---|---|---|---|---|---|---|
OpenCall.ai $0.10/ minute | 93 | 700 ms | 76% | 2000 | Low | |
Retell.ai $0.07 – 0.08 /min | 82 | 950 ms | 55% | 25 | Low | |
 Sierra AI $2 per successful outcome | 79 | 800 ms | 60% | 30 | Low | |
 PolyAI $0.25 /min (example case study) | 67 | 1700 ms | 72% | 25 | Medium | |
 Bland AI $0.09/min | 66 | 1100 ms | 50% | 15 | Low | |
 Phonely $396 (yearly) | 61 | 1200 ms | 52% | 17 | Medium | |
 Hey Rosie $49/mo (250 min) + $0.25/min | 57 | 950 ms | 60% | 1 | Low | |
 Smith.ai $3.25 /call (Starter 30 calls @ $97.50/mo) | 55 | 2300 ms | 40% | 30 | Medium | |
 8x8 XCaaS $60 per seat per month | 49 | 250 ms | 50% | 15 | Medium | |
 CloudTalk $25 – $50 /user/mo | 47 | 23 ms | 40% | 500 | Low | |
 Synthflow AI $0.08 /min (Growth) | 20 | 2300 ms | 45% | 20 | Low | |
 Balto.ai $100 / seat /mo | 12 | 100 ms | 0% | 40 | High |