Head to head
JustCall vs Synthflow
Written By Research Team
AI Outbound Calling
Fact Checked
All pricing verified against vendor documentation
Updated
Higher score
JustCall
A mature, fully-priced sales phone system that added a credible AI voice agent.
JustCall scores high for reasons that have nothing to do with AI hype: it publishes every seat price, and it holds the broadest certification set we found — SOC 2, HIPAA, ISO, PCI DSS, GDPR and CSA STAR. If your blocker is procurement rather than capability, this is the path of least resistance. The caveat matters though: its AI Voice Agent starts at $0.15/min, which is more expensive per minute than Bland, Retell or Vapi, and the core product is still a seat-based phone system.
Synthflow
Enterprise-only voice AI with ISO 27001 and EU hosting — and a $30,000 annual floor.
Synthflow has moved upmarket and now sells enterprise contracts only, starting at $30,000 per year. To its credit it publishes that floor, which most sales-gated vendors will not do. The compliance stack is the strongest here alongside Bland — SOC 2, HIPAA, GDPR and ISO 27001, with EU or US hosting. But there is no self-serve path at all: you cannot place a test call without going through sales.
Side by side
| Criterion | JustCall | Synthflow |
|---|---|---|
| Overall score | 87/100 | 69/100 |
| Rank | #3 | #8 |
| Type | AI-assisted dialer | Autonomous AI agent |
| Pricing model | Published | Sales-gated |
| Headline cost | $29–$89 per user/mo billed annually; AI Voice Agent from $0.15/min | Enterprise contracts start at $30,000 annually |
| Concurrency | Seat-based; unlimited minutes on Business tier | Custom concurrency planning with routing and escalation paths |
| Free trial | 14-day free trial, no credit card | None |
| Certifications | SOC 2, HIPAA, ISO, PCI DSS, GDPR, CSA STAR Level One | SOC 2, HIPAA, GDPR, ISO 27001, EU and US hosting options, MSA/DPA support |
Score by criterion
| Criterion | Max | JustCall | Synthflow |
|---|---|---|---|
| Pricing transparency | 20 | 19 | 8 |
| Outbound capability | 20 | 12 | 15 |
| Compliance & security | 20 | 20 | 19 |
| Integrations & extensibility | 15 | 14 | 14 |
| Time to first call | 15 | 15 | 4 |
| Scale & reliability | 10 | 7 | 9 |