Synthflow vs Retell AI: Features, Pricing and User Reviews 2026

Synthflow's published pricing covers its Enterprise plan, which starts at $30,000 per year, working out to about $2,500 a month. This is a starting price only, not a fixed final cost. The exact contract amount depends on factors such as call volume, number of concurrent calls, telephony setup, integrations needed, security requirements, and launch support.

The Enterprise plan includes an SLA and support terms, choice of native telephony or SIP trunking, custom call routing and escalation paths, and integrations with CRMs, calendars, contact center systems, webhooks, and APIs. It also covers security and data handling support such as MSA and DPA review, plus full implementation, onboarding, testing, training, and ongoing optimization.

Businesses need to contact Synthflow's sales team for a custom quote based on their specific needs.

Retell AI uses a pay as you go pricing model, so you only pay for what you use, with $10 in free credits to get started and no upfront commitment.

• Voice Agents: Priced at roughly $0.07 to $0.31 per minute, based on the LLM, voice, and telephony you choose.

• Chat Agents: Priced from about $0.002 per AI message, depending on the model used.

• Included Extras: 20 free concurrent calls, 10 free knowledge bases, call analytics, simulation testing, webhooks, and API access.

• Add-ons: Extra concurrency, knowledge bases, phone numbers, SMS, and quality features like PII redaction cost a small amount more per minute or per month.

For larger organizations, the Enterprise plan offers custom pricing with dedicated servers, single sign on, custom contracts, and 24/7 support.