Synthflow Review 2026
Last reviewed November 2026 by Théo Pascard
Overview
Synthflow builds AI voice agents that answer and place calls inside your existing phone system. Agents resolve routine requests, book appointments, detect voicemail, send SMS follow-ups, update the CRM during the call and hand over to staff with a summary and the full transcript. It connects to Zoom, Five9, RingCentral, 8x8, Twilio, Telnyx and Vonage, to Salesforce, HubSpot and Zendesk, and runs its own telephony with US, EU and Latin America points of presence. It claims SOC 2 Type II, ISO 27001 and HIPAA coverage and names Freshworks, Batteries Plus, Thryv and Yardi among its customers. On G2 it holds 4.5 out of 5 from 1,016 reviews. Pricing is an annual enterprise agreement with no published rate.
Enjyn Score
iWeighted across 5 axes, computed from public review data (G2, Capterra) and reweighted on our rubric — then overridden on the axes we operate first-hand.Who it's for
- →Contact centers and BPOs moving routine calls to AI
- →Multi-location brands answering high inbound call volume
- →Enterprises on Five9, RingCentral, 8x8 or Zoom phone systems
- →Regulated teams that need SOC 2, HIPAA and EU data residency
Not for
Capabilities
- Inbound and outbound AI voice agents inside an existing phone system
- Call routing, appointment booking and voicemail detection
- Handover to staff with a caller summary and full transcript
- CRM updates during the call (Salesforce, HubSpot, Zendesk, Freshworks)
- Native telephony with US, EU and Latin America points of presence
- SMS and WhatsApp agents (US workspaces) and web chat
- US or EU data residency and recording retention controls
- 200+ integrations, APIs and webhooks
Ratings & reviews
👍 Pros
👎 Cons
Pricing
| Tier | Price | Credits / mo | Notes |
|---|---|---|---|
| Enterprise | Custom | — | No public price. Sold only as an annual enterprise agreement scoped to call volume, phone system, integrations, security needs and launch support. No free plan, no trial and no per-minute rate on the pricing page. Checked 2026-11-12. |
The honest take
Where it breaks
The verdict
Alternatives
FAQ
How much does Synthflow cost?
Synthflow does not publish a price. Its pricing page sells a single annual enterprise agreement, scoped to your call volume, phone system, integrations, security needs and launch support, with no free plan, no trial and no per-minute rate. Pricing comes from a scoping call.
What do G2 reviewers say about Synthflow?
Synthflow has 1,016 G2 reviews averaging 4.5: 716 five-star, 239 four-star, 52 three-star, 6 two-star and 3 one-star. Ease of use (364 mentions), easy setup and integrations lead the strengths. Cost is the clear weak point, cited as expensive (145) and as cost limitations (97), ahead of the learning curve (59) and missing features (38).
Synthflow vs Retell AI: which one?
Both build AI phone agents. Synthflow targets contact centers and multi-location enterprises with an annual agreement, native telephony and launch support. Retell AI is self-serve and billed by the minute, with $10 of free credits, which suits builders, agencies and smaller teams.
Does Synthflow work with my phone system?
Synthflow lists built-in connections for Zoom, Five9, RingCentral, 8x8, Twilio, Telnyx, Vonage and Freshcaller. Genesys Cloud and other SIP-compatible systems need an enterprise setup, and Synthflow can also provide its own telephony.
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