# Synthflow AI vs Retell AI: What You Need to Know (July 2026)

> Synthflow's built-out (but $2,000/mo) whitelabel vs Retell's wrapper-it-yourself approach — agencies pay the agency tax either way.

HTML version: https://www.seldonframe.com/compare/synthflow-vs-retell-ai

Reviewed by Maxime Houle, Founder, SeldonFrame — facts checked July 2026.

## The short version

- **Synthflow AI pricing:** Usage-based from ~**$0.08–$0.09/min** + LLM & telephony **add-on**s; whitelabel listed at **$2,000/mo** or enterprise contracts from ~**$30k/yr**
- **Retell AI pricing:** **$0.07–$0.31/min** all-in, plus per-minute **add-on**s (KB, guardrails, PII, QA) and monthly fees per number
- **The real trade-off:** Synthflow's built-out (but **$2,000/mo**) whitelabel vs Retell's wrapper-it-yourself approach — agencies pay the agency tax either way.
- **The third option:** SeldonFrame ships the whole front office at **$29/mo** **flat** — see below

## Synthflow AI

Synthflow AI is a no-code voice-agent builder for phone receptionists and appointment booking.

- Best for: Non-technical teams launching phone agents from templates
- Pricing: Usage-based from ~$0.08–$0.09/min + LLM & telephony add-ons; whitelabel listed at $2,000/mo or enterprise contracts from ~$30k/yr
- AI receptionist: Yes — no-code voice agents with booking flows
- Website/CRM/booking behind the agent: None — voice agent only; CRM, website and calendar live elsewhere
- Whitelabel: Yes, but as a $2,000/mo add-on or enterprise bundle

## Retell AI

Retell AI is developer infrastructure for building voice and chat AI agents. It's priced per minute, built from separate pieces you assemble yourself.

- Best for: Developers building custom voice/chat agents on API rails
- Pricing: $0.07–$0.31/min all-in, plus per-minute add-ons (KB, guardrails, PII, QA) and monthly fees per number
- AI receptionist: Voice + chat agents via API — you build the receptionist yourself
- Website/CRM/booking behind the agent: None — no CRM, website or booking calendar
- Whitelabel: None built-in — third-party wrapper products fill the gap

## Side-by-side

| Feature | Synthflow AI | Retell AI | SeldonFrame |
|---|---|---|---|
| Best for | Non-technical teams launching phone agents from templates | Developers building custom voice/chat agents on API rails | Agencies & builders running AI front offices for clients |
| Pricing model | Usage-based from ~**$0.08–$0.09/min** + LLM & telephony **add-on**s; whitelabel listed at **$2,000/mo** or enterprise contracts from ~**$30k/yr** | **$0.07–$0.31/min** all-in, plus per-minute **add-on**s (KB, guardrails, PII, QA) and monthly fees per number | From **$29/mo** **flat** — **unlimited workspaces** (agency whitelabel from **$99/mo**) |
| AI receptionist (calls, SMS, chat) | Yes — no-code voice agents with booking flows | Voice + chat agents via API — you build the receptionist yourself | Native — AI receptionist answers, qualifies & books across voice, SMS & web chat |
| Website, CRM & booking behind the agent | None — voice agent only; CRM, website and calendar live elsewhere | None — no CRM, website or booking calendar | Included — multi-page website, CRM, booking calendar, intake forms, review requests in every workspace |
| Whitelabel & client workspaces | Yes, but as a **$2,000/mo** **add-on** or enterprise bundle | None built-in — third-party wrapper products fill the gap | Included — whitelabel client portal, per-client workspaces, custom domains, one-click multi-client deploy |
| AI usage costs | Per-minute, with engine/LLM/telephony pieces stacking | Billed **per minute**, per component | BYOK — bring your own AI (and Twilio) keys and pay providers at raw cost, zero markup |
| Sell / resell what you build | Yes — via the (paid) whitelabel program | Certified-partner referrals, but no built-in whitelabel product | Built in — publish agents to the marketplace or rent them via MCP (**5%** marketplace fee) |

Prices checked July 2026 on [Synthflow AI's pricing page](https://synthflow.ai/pricing) and [Retell AI's pricing page](https://www.retellai.com/pricing).

## If you need what BOTH do

Most people comparing Synthflow AI and Retell AI actually need the outcome underneath both: calls and chats answered, leads qualified, jobs booked into a real calendar and CRM, on a site the client owns. SeldonFrame ships that whole front office from one conversation at $29/mo flat (unlimited workspaces, bring-your-own AI keys), with whitelabel included for agencies.

- Honest deep-dives: https://www.seldonframe.com/alternative-to-synthflow and https://www.seldonframe.com/alternative-to-retell-ai
- Start free: https://www.seldonframe.com/signup · Book a demo: https://app.seldonframe.com/book/seldonframes-workspace-7798/default