Overview
Synthflow is a voice AI platform for building agents that handle inbound and outbound phone calls, with its own telephony network or bring-your-own SIP carriers. A visual Flow Designer defines call logic, and agents can book appointments, qualify leads, route calls, send SMS follow-ups and hand off to humans. The same agents can run on chat, SMS and WhatsApp, and Synthflow cites 200+ integrations including HubSpot, Salesforce, GoHighLevel and Cal.com. The published pricing is enterprise-focused, starting at $30,000 per year.
Label: Vendor-described — Captured from the vendor's own materials. Not independently verified.
Best for
- Businesses and agencies wanting AI agents to answer and book phone calls
- Teams scaling inbound and outbound calling with CRM and calendar integration
Key features
- Inbound and outbound AI phone agents
- Visual Flow Designer for call logic
- Appointment booking and call transfers
- Own telephony or bring-your-own SIP
- Call testing sandbox and auto-QA
- 200+ integrations including HubSpot and GoHighLevel
What it does
- Inbound and outbound AI voice agents
- Visual Flow Designer with multi-agent subflows
- Appointment booking, lead qualification and call routing
- Human handoff based on failed attempts or sentiment
- In-house telephony plus SIP trunking
- Call simulation testing and auto-QA
- Same agents across chat, SMS and WhatsApp
Use cases
Not mapped to a use case yet.
Drawbacks & cautions
- Only published plan is Enterprise, starting at $30,000 per year
- Pay-as-you-go per-minute rates are not listed publicly
- Telephony costs are not stated on the pricing page
What users say
Trustpilot reviewers generally like Synthflow's no-code call builder and natural voices. Negative reviews cite unreliable integrations, agents straying from instructions, slow support and billing issues.
What people like
- Easy to build call flows without coding uk.trustpilot.com
- Natural-sounding voices and low latency uk.trustpilot.com
- Useful scheduling, call transfer and CRM features for scaling calls uk.trustpilot.com
Common complaints
- Some integrations such as SMS triggers and webhooks are unreliable uk.trustpilot.com
- Agents sometimes ignore instructions or give off-topic answers uk.trustpilot.com
- Support is slow or generic, and key tools sit on enterprise plans uk.trustpilot.com
Scores are shown as each site published them on the date checked. They come from those sites' reviewers, not from us, and they never affect our rankings. Ratings based on fewer than 10 reviews are left out. The summaries are our own words, gathered Oct 22, 2026; follow the links to read the reviews.
Alternatives
- Goodcall — AI phone receptionist that answers calls 24/7, captures leads and books appointments
- My AI Front Desk — AI receptionist that answers calls 24/7, books appointments, texts and follows up with leads
- Retell AI — Platform for building AI voice agents that answer and make phone calls, book appointments and transfer to humans
- Smith.ai — AI and human receptionists that answer calls 24/7, qualify leads and book appointments
Evidence
| Fact | Label | Source | Observed |
|---|---|---|---|
| capabilities | Vendor-described | synthflow.ai | Oct 22, 2026 |
| hasApi | Vendor-described | synthflow.ai | Oct 22, 2026 |
| pricing | Vendor-described | synthflow.ai | Oct 22, 2026 |
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