Millis AI vs Retell AI

For no-code agency deploys with white-label resale, Retell AI offers partial white-label support and sub-account management, plus native integrations with Go High Level and HubSpot, which are core agency tools. Millis AI has no white-label capability on record, and its integrations list lacks both GHL and HubSpot. Both platforms offer no-code builders, but Retell's agency-relevant integrations and partial white-label capability tip the balance in its favor.

Both tools are API-first and support BYO LLM and BYO TTS voice, so core pipeline flexibility is comparable. Retell AI edges ahead for engineering teams because it includes a simulation and testing suite for agents, which is critical for validating custom pipelines before production. Retell also integrates natively with a broader set of developer-relevant connectors, including Twilio, Vonage, Go High Level, n8n, and HubSpot, versus Millis AI's smaller integration list. The testing suite alone is a meaningful differentiator for engineering-focused pipeline work.

For ecommerce support, compliance tooling, integrations, and reliability matter. Retell AI offers SOC 2 Type II certification, GDPR tooling, recording consent compliance, and native integrations with HubSpot and Go High Level, both common in ecommerce stacks. Retell also includes a built-in knowledge base and warm transfer to human, which are valuable for order support flows. Millis AI has a lower base price at $0.02 per minute versus Retell's $0.07 per minute, a notable cost advantage, but Retell's broader compliance credentials and richer native ecommerce-relevant integrations tip the balance.

For HIPAA-bound healthcare workflows, compliance certifications are decisive. Retell AI holds SOC 2 Type II certification and offers a HIPAA BAA, even if restricted to enterprise plans. Millis AI has no documented HIPAA BAA or SOC 2 certification. Retell also includes GDPR tooling and consent and recording compliance tooling, further strengthening its compliance posture. While Millis AI is cheaper at $0.02 per minute base versus Retell's $0.07 per minute, cost cannot override the absence of critical healthcare compliance infrastructure.

Both tools support native outbound campaigns, SIP trunking, and no-code builders. However, Retell AI adds enterprise-relevant advantages: SOC 2 Type II certification, GDPR tooling, consent and recording compliance, warm transfer to human, a built-in knowledge base, a simulation and testing suite, and native Go High Level plus HubSpot integrations. These features matter in outbound sales where compliance, CRM connectivity, and agent quality assurance are critical. Retell's real cost tops at $0.415 per minute versus Millis at up to $0.66 per minute, and Retell includes 20 concurrent calls on the base plan. Millis base price of $0.02 per minute is lower, but the broader compliance and integration stack tips outbound sales toward Retell.

For an SMB watching costs, Millis AI's base price of $0.02/min versus Retell AI's $0.07/min is a 3.5x difference, directly reducing the per-call cost of a receptionist workload. Both tools offer a no-code builder, self-serve signup, outbound campaigns, SIP trunking, and number provisioning, so feature parity is high. Millis AI's real production cost starts at $0.06/min versus Retell's $0.085/min, reinforcing that cost advantage. Retell has SOC 2 and GDPR tooling, which matter less to a typical SMB receptionist than pricing does. Millis holds the edge on affordability for high-volume booking and after-hours coverage.