Retell AI vs Voiceflow

In short

• Both: Choice of models, API, Builds agents and workflows, Search over your data, Traces and evaluates
• Only Retell AI states: Self-hosted

Retell AI

Retell AI builds voice, chat, and SMS agents that answer questions, complete tasks, route calls, and hand off to people.

Plans

Pay as you go

• $0.07-$0.31 / min
• $0.002+ / msg

• Full platform access
• Pre-built Agent Templates
• Call Analytics and Transcripts
• Simulation Testing
• Webhooks and API Access
• 20 Free Concurrent Calls

Enterprise Plan

Price on request

• Dedicated Implementation Support (add-on)
• Custom MSA/DPA terms
• Role-based Access Control
• Dedicated Stable Server (add-on)
• Custom SSO
• High Cap on Concurrent Calls

Prices checked 2026-09-25 on the maker’s page.

Capabilities

• Choice of models — “Choose your options LLM GPT 5.5 GPT 5.4 GPT 5.2” source
• Self-hosted — “Deploy Retell within your own infrastructure to meet strict security and data residency requirements.” source
• API — “Build and orchestrate custom communication experiences through a flexible API.” source
• Builds agents and workflows — “Build, update, test, and deploy AI voice agents without relying on Retell for every change.” source
• Search over your data — “AI uses existing knowledge” source
• Traces and evaluates — “Every call is transcribed and available for review, so you evaluate 100 percent of interactions instead of a manual sample.” source

Security

• SOC 2 Type II — “SOC 2 Type 2 Report” source
• SOC 2 — “SOC 2 Type 1 Report” source
• ISO 27001 — “ISO 27001:2022 Certificate Of Registration” source
• GDPR — “GDPR commitments” source
• HIPAA — “To obtain a signed Business Associate Agreement (BAA) or Data Processing Agreement (DPA), visit our Legal agreements portal:” source

Latest updates

• 2026-08-24 Retell Workflows, Brex top 25, and more

  Retell Workflows has launched; transcription defaults to call IDs; GPT-5.6 and GPT Realtime 2.1 are live in the agent builder.

• 2026-07-02 Conductor, higher free-tier token limits, and more

  Conductor is live; every change gets simulated before it ships; free LLM token allowance raised to 4,000; documents parse more accurately.

• 2026-06-19 Live Call Monitoring, Custom Dashboards, Built-in CRM, Colloquial Model, Expressive Mode, and more

  Built-in CRM syncs with Salesforce and HubSpot; Live Call Monitoring gives a real-time view of active conversations.

Voiceflow

Voiceflow helps teams build, test, deploy, and monitor AI agents for customer conversations across chat, voice, and other channels.

Plans

Not read from the maker’s page yet.

Prices checked 2026-09-25 on the maker’s page.

Capabilities

• Choice of models — “Use any AI vendor, including OpenAI and Anthropic, to power agent responses, logic, and actions.” source
• API — “Launch Agents with Voiceflow's web chat UI or any custom interface using the Dialog API.” source
• Builds agents and workflows — “Teams use Voiceflow as a central collaborative platform to build, launch, and scale AI Agents for any use case.” source
• Search over your data — “Build a knowledge base Import data and documents to the Knowledge Base to allow Agents to respond using curated data.” source
• Traces and evaluates — “LLM-powered evaluations give you custom insights at scale, helping teams make faster decisions about agent iterations.” source

Security

• SOC 2 Type II — “SOC 2 Type II” source
• SOC 2 — “SOC 2 Type II” source
• ISO 27001 — “ISO 27001” source
• GDPR — “GDPR View compliance” source
• HIPAA — “HIPAA View compliance” source
• Not trained on your data — “Voiceflow does not use customer data to train any machine learning or AI models.” source

Latest updates

• 2026-09-24 Live agent handoff

  Users on all plans can add the Handoff step to a chat agent and route conversations to a live agent.

• 2026-09-16 Voiceflow Core 4.2 (4.2)

  Voiceflow Core 4.2 has been released as the newest agent model; agents running 4.1 will move to 4.2 automatically.

• 2026-09-10 Instruction patching

  Agent instructions, global prompts, and playbook instructions can be read, searched, and patched line by line through the API.