Voice AI that scales past the entry point.

Lightweight voice builders are brilliant at onboarding. Give Thoughtly a straightforward use case and a small team, and you'll have an agent taking calls in an afternoon.
Thoughtly is great for getting started, but it can fall short in production. When you need things like custom models, warm transfers, multilingual support, or deeper analytics and testing, you quickly run into limits and end up needing developer help anyway.
Retell is voice AI that works in production. It’s easy to set up, but powerful enough to handle real workflows, with features like transfers, branded calls, analytics, and compliance built in. Tell it what you want done and it takes care of the call.
You start with a call. Retell helps you finish with a production deployment at scale.
An agent that scales, not one you outgrow.
| Features | ![]() | |
|---|---|---|
| LLM flexibility | LLM-agnostic with custom model support | Locked model stack |
| Telephony stack | Native SIP, warm transfer, IVR/DTMF | BYOC via Twilio and Telnyx |
| Answer rates | Branded caller ID and verified numbers | Not supported |
| Languages | 55+ languages natively supported | 30+ languages |
| Knowledge Base | Pulls the right info from your docs | Relies on LLM memory |
| Post-Call Analysis | Auto insights for every call | Not supported |
| Drag & Drop | Low/no code capabilities | No-code capabilities |
| Compliance | HIPAA, SOC 2 Type 1 & 2, GDPR | HIPAA only |
A voice platform built to scale







Thoughtly excels when you're exploring voice AI, not depending on it.
Retell excels when the call has to work and keep working as you scale.