Which one, by use case
| If you care about | Leads | Synthflow | Vapi |
|---|---|---|---|
| Lowest cost at 1,000 minutes a monthNeeds a price at this volume from both vendors | Can't compute | Not computable | $50 |
| Lowest starting priceA starting price is missing for one or both | Can't compute | Contact sales | $29/mo |
| Trying it freeNo free plan found for either | Not found | Not found | One-off allowance: $5 free credits to start, then pay per minute |
| Buying without a sales call | Vapi | Sales-led | Self-serve + sales |
| No long contract | Not found | Annual commitment for enterprise plan | Not found |
| Most voice agent platforms checks statedCounted from quotes on each vendor's site, not tested | Vapi | 7 of 8 | 8 of 8 |
| Security reviewSOC 2, GDPR, HIPAA BAA and SSO, in the vendor's own words | Vapi | 3 of 4 stated | 4 of 4 stated |
| Fewest price rises on recordFrom archived copies of each pricing page | Tie | 0 since 2024Q4 | 0 since 2026Q2 |
Each row is computed from the two records, with no overall winner. "Not found" means a record doesn't state it, so that row can't be decided.
Plans side by side
| Synthflow plan | Price | Included |
|---|---|---|
| Enterprise/year"Enterprise contracts start at $30,000 annually. Final pricing is scoped around call..." | Quote | – |
Read from Synthflow's pricing page on Oct 29, 2026.
| Vapi plan | Price | Included |
|---|---|---|
| Core/ month"unity email support without sla choose your success package core for builders & early..." | $29 | 5 phone numbers |
| Pro$999/mo minimum"$999/mo minimum" | $999 | 10 phone numbers |
| No Success Package/min"Pre-paid, $0.05/min Vapi hosting." | $0.05/minute | – |
| Premier"Direct sales only" | Quote | – |
Read from Vapi's pricing page on Oct 29, 2026.
Voice agent platforms checks
| Check | Synthflow | Vapi |
|---|---|---|
| Inbound calls | Stated"Deploy AI voice agents across inbound and outbound call flows" | Stated"Twilio Inbound$0.008 / min" |
| Outbound calls | Stated"Deploy AI voice agents across inbound and outbound call flows" | Stated"Twilio Outbound$0.014 / min" |
| Phone numbers included | Stated"Synthflow Native Telephony" | Stated"1 included Vapi phone number" |
| Choose your AI model | Not found | Stated"Full model catalog" |
| Choose the voice | Stated"Shape the tone, voice, and workflows." | Stated"Configure everything from voice and conversation flow, to telephony and integrations." |
| Public API | Stated"API Docs" | Stated"API/CLI access" |
| Connects to your tools | Stated"CRM, calendar, contact-center stack, webhook, API, and knowledge-source integrations" | Stated"Webhook and custom model integrations" |
| HIPAA option | Stated"Synthflow is fully compliant with SOC 2, HIPAA, GDPR, and ISO 27001" | Stated"HIPAA eligible data handling. Standard Data Processing Agreement and Business Associate Agreement" |
Fine print
| Term | Synthflow | Vapi |
|---|---|---|
| Billed beyond usage | Excess usage beyond monthly usage limits is charged at the fees in the Subscription Plan; limits do not..."These Usage Limits are defined per month and do not roll over to the next month." | Not found |
| Contract | Annual commitment for enterprise plan"Enterprise contracts start at $30,000 annually." | Not found |
| Refunds | Not found | Non-consumption fees may be refunded pro rata at Vapi's discretion; usage fees non-refundable"it will be calculated on a pro-rata basis according to the number of unused days remaining in the..." |
| Auto renew | Not found | Core is pre-paid and auto-renews"Pre-paid, auto-renew" |
| Price change notice | Not found | Advance notice of material pricing changes, with option to cancel"If we introduce material changes to pricing, we will notify you in advance and will provide you an option..." |
Security and your data
| Question | Synthflow | Vapi |
|---|---|---|
| Trains AI on your data? | Not found | may be retained to help train and improve AI models"Call recordings, transcripts and logs may be retained to help train and improve the AI models, in..." |
| HIPAA (signs a BAA) | available"Synthflow’s infrastructure is certified across SOC 2, HIPAA, PCI DSS, and GDPR" | available as $2,000/month add-on on any package"HIPAA eligible data handling. Standard Data Processing Agreement and Business Associate Agreement" |
| SOC 2 | yes"Synthflow’s infrastructure is certified across SOC 2, HIPAA, PCI DSS, and GDPR" | yes"SOC 2, HIPAA, and PCI compliant" |
| GDPR | yes"Synthflow’s infrastructure is certified across SOC 2, HIPAA, PCI DSS, and GDPR" | GDPR rights covered"Your Data Protection Rights Under General Data Protection Regulation (GDPR)" |
| Single sign-on | Not found | Premier"Custom RBAC + ZDR + SSO" |
The vendors' own words. We don't audit security claims. The full trust table.
Price history
No price changes on Synthflow's pricing page since 2024Q4, across 7 archived reads.
No price changes on Vapi's pricing page since 2026Q2, across 3 archived reads.
From archived copies of each pricing page in the Internet Archive, one per quarter, in USD. All price changes.