Guide · AI Receptionists
The cheapest developer voice-AI platform per minute isn't the one with the lowest headline rate
Vapi's $0.05 and Retell's $0.055 are platform-only rates; once you add the LLM and telephony they pass through, Bland's all-in $0.12–$0.14 stops looking expensive.
If you read the pricing pages straight, Vapi wins this category at $0.05/min and Retell is next at $0.055/min. Both numbers are real, and both are misleading, because neither is a price you can actually run a call on. Vapi’s $0.05 is a platform fee; the language model, speech-to-text, and text-to-speech are passed through at cost on top. Retell’s $0.055 is voice infra only — its own page quotes an all-in range of $0.07–$0.31/min once you add an LLM and the $0.015/min US telephony. The honest floor in this market is not $0.05. It’s closer to $0.07, and the only vendor that quotes a single number you can take at face value is Bland, at $0.12–$0.14/min all-in.
What each headline rate actually covers
The developer platforms here bill in fundamentally different ways, and the difference is entirely in what the rate bundles — where one still publishes a rate at all.
| Platform | Headline rate | What it includes | Honest floor |
|---|---|---|---|
| Vapi | $0.05/min | Platform fee only — LLM/STT/TTS passed through at cost | $0.05 + model stack (unquantified on page) |
| Retell AI | $0.055/min | Voice infra only | $0.07/min all-in (infra $0.055 + telephony $0.015) |
| Synthflow | none published | Pay As You Go no longer listed as of 2026-09-27; Enterprise contracts from $30,000 annually | — |
| Bland | $0.12–$0.14/min | All-in: LLM + STT + TTS + telephony | $0.12/min (Build) to $0.14/min (Start) |
Vapi is the trap. The $0.05/min is genuinely the lowest platform fee on the table, and if you bring your own keys it stays low — but the dataset’s own provenance is explicit that “true end cost depends on chosen models,” and the page does not quantify the pass-through. You cannot price a Vapi minute from the pricing page alone. What you can price is the HIPAA add-on, which is a flat $2,000/mo — a number that inverts the entire “cheapest” ranking the moment compliance enters the picture.
Retell is more transparent: $0.055 infra plus $0.015 telephony gives a $0.07 floor, but the published ceiling is $0.31/min depending on which LLM you wire up. That’s a 4.4x spread inside one vendor, and the floor only holds if you run the cheapest model.
Synthflow has left the per-minute comparison. Its Pay As You Go plan — a $0.09/min voice engine with the LLM at $0.02–$0.05/min and telephony on top, last seen 2026-06-27 — is no longer listed on its pricing page as of 2026-09-27. The page now sells only sales-led Enterprise contracts that “start at $30,000 annually,” so there is no Synthflow minute left to price from the page.
The all-in comparison flips the order
Once you normalize to what actually leaves your account per minute, the headline ranking falls apart:
- Retell, cheapest LLM: $0.07/min all-in.
- Bland Build: $0.12/min all-in (with a $299/mo platform fee).
- Bland Start: $0.14/min all-in, $0/mo platform fee.
- Vapi: $0.05 platform fee plus an unquantified model stack — possibly cheapest, possibly not, unknowable from the page.
Bland’s structure rewards volume through the platform fee rather than the per-minute rate: Start is $0.14/min at $0/mo and Build drops to $0.12/min for a $299/mo fee. Its Scale tier, $0.11/min for $499/mo, was last seen on 2026-09-02 and is no longer listed as of 2026-09-27; the page’s plan comparison now reads Start, Build, Enterprise. The crossover still matters. At low volume, Start’s zero platform fee wins; the point where Build’s $299 beats Start is around 15,000 minutes a month ($299 ÷ the $0.02/min saving). Below that threshold, the free Start tier at $0.14/min is the rational Bland choice.
So which is actually cheapest?
For a buyer who wants the lowest defensible per-minute number with no assembly and no surprise line items, Bland is the answer — $0.14/min on the free tier, dropping to $0.12/min on Build, with nothing passed through. Its provenance is the cleanest in the dataset: a single all-in talk rate, HIPAA-eligible with a signed BAA on its Enterprise tier, no model wiring required.
Retell can beat it — $0.07/min — but only at the floor of a $0.07–$0.31 range, and only if you accept the cheapest LLM and US-only $0.015 telephony. Vapi’s $0.05 is the lowest platform fee and the highest uncertainty: cheap if you optimize your own stack, opaque if you don’t, and $2,000/mo more if you need HIPAA. Synthflow no longer publishes a per-minute rate at all; its page quotes Enterprise contracts from $30,000 a year.
The rule for this category: a per-minute platform’s headline rate tells you what the vendor charges for its slice, not what the call costs. Bland prices the whole call; everyone else prices a part of it and lets you discover the rest. If you want a number you can put in a budget today, it’s Bland’s $0.12–$0.14. If you’re willing to engineer and monitor a model stack, Retell’s $0.07 floor — or Vapi’s unknowable-but-low platform fee — can go lower.