Synthflow pricing and review

I run Reachkit, which sells cold email software, not phone agents. I checked every Synthflow price here on October 16, 2026, against Synthflow’s pricing page, billing docs and terms.

Synthflow pricing starts at $30,000 a year, sold through its sales team. As of October 16, 2026, synthflow.ai/pricing lists one plan, Enterprise: “Enterprise contracts start at $30,000 annually”, or $2,500 a month. The price is scoped on call volume, concurrency, phone setup, integrations, security and launch support. It includes an SLA, telephony and onboarding.

What isn’t public: the per-minute rate, included minutes, overage, concurrency and phone number costs. The usage docs bill per second from when caller and agent connect, invoiced per whole minute. Unanswered calls count as 5 seconds, failed calls are free, and billing stops at a transfer.

The terms are strict. Synthflow’s US terms (May 2026) bill in advance, bind you to the whole contract period, make fees non-refundable and let unused usage expire each billing period unless your order form includes carryover.

The old plans are gone. The docs say the Pro, Growth and Agency plans “are no longer sold”; existing workspaces keep their limits. Synthflow’s August 2025 blog post quoting $0.08 a minute with no required contract still ranks, as do third-party pages listing monthly plans. Both describe the old model.

What a typical setup costs: the one public number is the floor, at least $30,000 for a year. Your rate per minute only appears in the quote.

Synthflow builds AI agents that hold phone conversations, plus chat agents for web, SMS and WhatsApp. It was founded in Berlin in 2023 as a no-code builder, and its homepage now pitches enterprise phone automation.

You describe the agent in a prompt, and Aurora, an assistant inside the dashboard, drafts the first version. You then edit the prompt or map the conversation in Flow Designer, a node-based visual editor. Agents can book appointments, transfer calls, call your APIs, use a knowledge base and send a text or email after the call.

Agents run on numbers bought in Synthflow, your own SIP line, or connectors for Five9, Genesys Cloud, Talkdesk, RingCentral, Twilio and others. Outbound campaigns dial lists of up to 1,000,000 people through the API, on Enterprise plans. Integrations include GoHighLevel, Salesforce, HubSpot and Zapier, next to webhooks and a hosted MCP server, the standard way AI assistants like Claude and ChatGPT use other apps.

Strengths

• Building without code. G2 review summaries put ease of use and setup at the top of the praise, helped by the Flow Designer, templates and Aurora.
• Fits a contact center. SIP plus connectors for Five9, Genesys, Talkdesk and RingCentral put agents inside an existing phone system.
• Security paperwork. The pricing page lists SOC 2, ISO 27001, GDPR and HIPAA, with a BAA available and EU or US hosting.
• Open to builders. About 100 API endpoints, signed webhooks, the MCP server and official Claude and ChatGPT connectors.
• Current models. The changelog adds GPT-6 and ElevenLabs v4 voices.

Drawbacks

• A high entry price. No self-serve plan, and contracts start at $30,000 a year with minute rates negotiated. Cost is the top complaint in G2 review summaries.
• Little room to change course. Under the standard terms, fees are non-refundable, ordered volume can’t be lowered, and unused minutes expire unless carryover is agreed.
• Agencies lost rebilling. On September 15, 2026, Synthflow removed built-in client billing, so agencies invoice clients themselves.
• Depth takes time. G2 review summaries mention a learning curve for advanced features.

Synthflow’s pricing page cites 4.5 out of 5 on G2 from more than 1,000 reviews (October 2026). Reviewers praise building agents without heavy technical setup and complain most about cost. G2’s segment breakdown puts 92.8% of reviewers at small businesses, so many reviews likely predate the move to Enterprise-only contracts.

Trustpilot shows 4.1 from 215 reviews, but only 6 arrived in the last 12 months and the four newest are one-star. Two of those are about the product: one reviewer says billing continued months after cancelling (April 2026), another that agents strayed from their instructions (May 2026). Those are single reports, not a pattern, and Trustpilot notes Synthflow hasn’t replied to negative reviews. The Capterra listing has no reviews.

Synthflow fits enterprises, BPOs and contact centers with many routine calls, a budget past $30,000 a year, and a need for security reviews and connectors into Genesys or Five9. Synthflow’s homepage cites Freshworks automating up to 65% of routine voice requests.

Look elsewhere if you’re a small business or agency that wants to test a voice agent month to month: the pricing page lists no such plan. The same goes for cold-calling a bought list, since Synthflow’s terms put the legality of your input and spam-call complaints on you. My view: a phone agent earns its cost on people who already raised a hand, and email is a cheaper way to find them.

• Retell AI: voice agents from $0.07 a minute on prepaid credits, with no platform fee or contract. See the Retell AI profile and Vapi vs Retell AI.
• Vapi: a developer platform at $0.05 a minute for hosting, plus the model, voice and phone providers you pick. See the Vapi profile and Vapi alternatives.
• Bland: phone agents at $0.14 a minute on Start, or $299 a month plus $0.12 a minute on Build. See the Bland profile.
• GoHighLevel: the agency CRM Synthflow integrates with has its own Voice AI, at $0.045 a minute for the engine plus voice, model and phone charges. See the GoHighLevel profile.
• Reachkit (our product): if you wanted Synthflow to start conversations with cold prospects, Reachkit does that by email, month to month from $39. Describe the campaign in a sentence and it finds verified leads (1,000 credits a month on Growth), writes the sequence, sends from warmed inboxes and labels replies like Meeting Requested. It doesn’t call anyone or answer replies for you.