Compare · Prices checked October 20, 2026
Retell AI vs Synthflow (2026)
Published starting prices: Retell AI, $0.07/min (Pay as you go, from). Synthflow, $30,000/yr (Enterprise minimum). Side-by-side public pricing, what each does, real use cases and who each suits, all from our listings with sources. We haven't tested either hands-on.
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Voice platform
Retell AI
Pay-as-you-go platform for building voice agents. Cheapest per minute, but you (or an agency) build the receptionist yourself.
≈ $115/mo at 300 calls
Ranked in 1 industry$0.07/min
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Receptionist
Synthflow
No-code voice-agent platform that has moved to enterprise contracts. Listed because it's widely recommended; it is not a small-office product at current pricing.
≥ $2,500/mo at 300 calls
Subscription$30,000/yr
Quick answer
- Cheaper: Advertised entry prices: Retell AI $0.07/min, Synthflow $30,000/yr. At about 300 calls a month, our estimate of the real bill is ≈ $115/mo + build time for Retell AI and ≥ $2,500/mo (contract minimum) for Synthflow, so Retell AI is cheaper at that volume. Your bill depends on your call volume and call length; the math is on each product page. Checked October 20, 2026.
- Free plans: Retell AI: no $0 plan on its pricing page (checked October 20, 2026); free trial or free start: Free sign-up; pay for usage. Synthflow: no $0 plan on its pricing page (checked October 20, 2026).
Pricing side by side
| Item |  Retell AI |  Synthflow |
|---|---|---|
| Starting price | $0.07/min (Pay as you go, from) | $30,000/yr (Enterprise minimum) |
| Pricing model | Pay per use | Subscription |
| Free plan | No | No |
| Real bill at 300 calls/mo (our estimate) | ≈ $115/mo + build time | ≥ $2,500/mo (contract minimum) |
| Free trial | Free sign-up; pay for usage | None public |
| Plans |
|
|
| Pricing note | Default calculator: voice infra $0.055 + LLM ~$0.04 + TTS $0.015 per min, plus telephony $0.015/min and $2/mo per number. | Older self-serve plans quoted on third-party sites no longer appear on the pricing page. |
| Checked | October 20, 2026 | October 20, 2026 |
| Source | Vendor pricing page | Vendor pricing page |
Copied from each vendor's public pricing page on the date shown. "not published" means the vendor doesn't publish it; we don't guess. Prices change; confirm with the vendor.
Features and details from our listings
| Item | Retell AI | Synthflow |
|---|---|---|
| What it is | Pay-as-you-go platform for building voice agents. Cheapest per minute, but you (or an agency) build the receptionist yourself. | No-code voice-agent platform that has moved to enterprise contracts. Listed because it's widely recommended; it is not a small-office product at current pricing. |
| Type | Developer voice AI platform (build your own) | Voice AI platform (enterprise) |
| Listed under | AI receptionists, Voice & phone agents | AI receptionists, Voice & phone agents |
| 24/7 answering | yes | yes |
| Appointment booking | Yes, if you build it | Yes (calendar integrations) |
| Integrations | Webhooks, API, Twilio/Telnyx/SIP | CRM, calendar, contact-center, webhooks, API |
| Bilingual | Yes (model dependent) | Yes (30+ countries) |
| Call transfer | Yes | Yes |
| HIPAA | HIPAA/BAA listed in plan comparison (confirm which plan) | Security review/DPA in contract; HIPAA not stated on pricing page |
| Setup fee | None (but you build it) | Scoped in contract |
| Verified public use cases | 1 | 0 |
Use cases
Retell AI
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Use caseVoice
A freelance automation builder made a Retell AI voice agent for a residential estate agency that answers after-hours calls and shares property details from the agency's listings.
Oct 2025Contra
Where our industry rankings place it: Medical Practices #4.
Synthflow
We haven't found a verified public use case for Synthflow yet.
Use cases are summarised in our own words from the linked public post; vendor case studies are labelled. All use cases.
Who each is best for
- Pay per use
Retell AI is best for
- Ranked for: Medical Practices. In medical practices: For practices with an IT partner: lowest running cost and a HIPAA/BAA path, but you must build it.
- Type: Developer voice AI platform (build your own). Real bill at 300 calls: ≈ $115/mo + build time.
- Strengths: Lowest running cost; Huge positive review base; HIPAA path.
- Watch out: Not a finished product: needs building and upkeep; Costs vary with model choice.
- Subscription
Synthflow is best for
- Type: Voice AI platform (enterprise). Real bill at 300 calls: ≥ $2,500/mo (contract minimum).
- Strengths: Mature platform, many reviews; Done-for-you enterprise launch.
- Watch out: $30k/yr minimum rules out small offices; Not self-serve any more.
From our listing data (jobs, public pricing, industry rankings, pros and cons); not a hands-on test. Full details: Retell AI · Synthflow.
FAQ
Which is cheaper, Retell AI or Synthflow?
Advertised entry prices: Retell AI $0.07/min, Synthflow $30,000/yr. At about 300 calls a month, our estimate of the real bill is ≈ $115/mo + build time for Retell AI and ≥ $2,500/mo (contract minimum) for Synthflow, so Retell AI is cheaper at that volume. Your bill depends on your call volume and call length; the math is on each product page. Checked October 20, 2026.
Is Retell AI free? Is Synthflow free?
Retell AI: no $0 plan on its pricing page (checked October 20, 2026); free trial or free start: Free sign-up; pay for usage. Synthflow: no $0 plan on its pricing page (checked October 20, 2026).
How much does Retell AI cost?
Retell AI lists Pay as you go: $0.07-$0.31/min (Full platform, 20 concurrent calls, 10 knowledge bases); Enterprise: Contact sales (Custom BAA/MSA, SSO, dedicated support). Our estimate of the real bill at about 300 calls a month: ≈ $115/mo + build time. Checked October 20, 2026 on the vendor's pricing page.
How much does Synthflow cost?
Synthflow lists Enterprise: from $30,000/year (Scoped by volume, concurrency, integrations). Our estimate of the real bill at about 300 calls a month: ≥ $2,500/mo (contract minimum). Checked October 20, 2026 on the vendor's pricing page.
Did AITeamGuide test them?
Not hands-on. This comparison is built from each vendor's public pricing page (with the date we checked it), published product information and credited public use cases.
Can a vendor pay to win this comparison?
No. Nothing here is paid. Paid placements on AITeamGuide are always labelled "Sponsored" or "Featured" and never change a comparison or ranking.
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Work at Retell AI or Synthflow? Vendors can claim their listing for free or feature it with a label that says "Sponsored"; paid status never changes the order on this page. Building a different agent? List it here.
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