TL;DR: Synthflow is the best no-code AI voice agent builder for agencies and small businesses – you can launch a phone agent in minutes without writing code, and its white-label and rebilling features let agencies resell it as their own. It leans on best-of-breed providers under the hood and integrates with 200+ apps; the trade-offs are pricing that is mid-transition and turn latency that lags the fastest developer platforms. App Score: 7.3/10.

How we scored Synthflow

Weighted against our AI voice agent rubric. Sub-scores out of 10; weight in brackets.

Voice quality & latency (25%)7.0
Build power & flexibility (20%)6.5
Integrations & telephony (15%)8.5
Ease of setup (15%)9.0
Value (15%)6.5
Reliability & scale (10%)6.5
Weighted total7.3/10

Our independent score, from our own weighted rubric and verified pricing, kept separate from any sponsorship. Our methodology.

Starting pricePay-as-you-go (~$0.09/min voice-engine floor)
Real all-in~$0.15-0.37/min with LLM and telephony
EnterpriseFrom $30,000/yr (10,000 min/mo)
Best forAgencies and SMBs that want no-code and white-label
StandoutNo-code builder + agency white-label and rebilling
TypeNo-code builder

Key features of Synthflow

  • No-code drag-and-drop Flow Designer with branch and jump-to routing, real-time booking and call-transfer nodes.
  • Function/tool calling via Custom Actions (HTTP requests mid-call) for CRM writes, lookups and workflow triggers.
  • Bring-your-own LLM, voice and transcription providers (ElevenLabs, Deepgram and others) via API keys.
  • Phone numbers in-platform or BYO carrier; 20+ carriers and SIP trunking on Enterprise; inbound and outbound.
  • 200+ integrations including HubSpot, GoHighLevel, Salesforce, Calendly, Zapier and Make.
  • Strong native white-label: custom domain and branding, subaccounts and Stripe rebilling to resell under your own brand.

Who Synthflow is best for

Synthflow is for agencies and non-technical teams that want to launch and resell voice agents without engineering. Its no-code builder is the most approachable on our list, and the white-label toolkit makes it a genuine agency business in a box. Developers who want deep programmatic control will prefer Vapi, Retell or LiveKit.

Pros and cons

Pros

  • Best ease of setup on our list (9.0): genuinely no-code, fast to launch.
  • Excellent agency white-label: custom branding, subaccounts and Stripe rebilling.
  • 200+ integrations and BYO carrier/LLM flexibility.
  • Backed by a $20M Accel Series A, with strong SMB and agency adoption.

Cons

  • Turn latency lagged peers in a third-party benchmark (~3.15s median), and reviews note occasional stability issues.
  • Pricing is mid-transition: the official page shows only pay-as-you-go and $30,000/yr Enterprise, and older monthly tiers are unverified.
  • Less programmable depth than developer-first platforms.

Verdict

Synthflow is the top no-code pick for agencies and small businesses that want to launch, brand and resell voice agents without code. It wins on ease of setup and white-label, integrates widely, and is well funded. Watch the latency and confirm current pricing directly, since the model is mid-transition. See how it stacks up in our best AI voice agents guide.

Related guides

Compare more in our cluster: AI Voice Agent Pricing and Best No-Code AI Voice Agent Builders.

Frequently Asked Questions

Is Synthflow no-code?

Yes. Synthflow is a no-code voice agent builder with a drag-and-drop Flow Designer, and it scores highest on our list for ease of setup (9.0). It is aimed at agencies and non-technical teams who want to launch a phone agent in minutes.

How much does Synthflow cost?

Synthflow’s current official pricing is pay-as-you-go, with a voice-engine floor around $0.09/min and realistic all-in of roughly $0.15-0.37/min once LLM and telephony are added, plus Enterprise from about $30,000/year. Older fixed monthly tiers are no longer confirmed on the official page.

Can I white-label Synthflow for my agency?

Yes. Synthflow has strong native white-label: custom domain and branding, subaccount management and Stripe rebilling, so agencies can resell voice agents under their own brand and collect payment directly.

Is Synthflow good for developers?

It can be, thanks to a public API and BYO-LLM support, but Synthflow is built no-code first. Developers who want deep programmatic control and the widest SDK coverage will usually prefer Vapi, Retell or LiveKit.

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