Vapi vs Retell AI vs Bland AI: which voice agent platform fits your build?
All three platforms let you build an AI agent that makes and takes phone calls, but they price and package that call very differently. Vapi charges a low $0.05/min platform fee and passes every other cost (model, voice, transcription, phone line) straight through to you, so your real bill depends entirely on the stack you choose. Retell AI folds the voice pipeline into one number starting near $0.07/min, then adds the model and voice on top. Bland AI sells the most predictable number: one flat rate, from $0.09 to $0.14/min, that already includes the model and voice, with telephony billed separately. None of the three is "cheapest" outright — it depends on your volume and how much control you want over the stack.
 |  |  | |
|---|---|---|---|
| What it does | Build voice agents that make and take phone calls | Build voice agents that make and take real calls | Phone agents that handle calls start to finish |
| Pricing | Usage-based (from $0.05/min + provider costs) | Usage-based (from ~$0.07/min, bundled voice layer) | Usage-based (from $0.09-$0.14/min, model+voice included) |
| Open source | No | No | No |
| Self-hostable | No | No | No |
| Best for | Teams that want to choose their own LLM, voice and STT provider | Teams that want a cleaner single rate without full DIY provider management | Teams that want one predictable number and are willing to pay more for it |
| Upvotes | 9 | 1 | 1 |
The verdict
Vapi's $0.05/min is the lowest headline rate of the three, but it's the smallest line on the bill. You bring your own LLM, TTS, STT and phone provider, so the real all-in cost depends on what you pick: Vapi's own calculator example totals about $0.082 to $0.129 per minute, and premium providers, longer prompts and external carrier fees push it higher. Best suited to teams with an engineer who wants that control.
Retell bundles its voice infrastructure into one number starting around $0.07/min, with the model and voice priced on top of that. It sits in the middle: less assembly than Vapi, more transparency into what you're paying for than Bland. A reasonable default if you want fewer billing relationships than Vapi without giving up model choice entirely.
Bland's pitch is one flat rate ($0.09-$0.14/min) that already includes the model and voice, so budgeting is simpler than either competitor. Telephony is billed separately, and the lowest rate requires a $499/month platform fee, so it's most competitive at higher call volume.
Frequently asked questions
Which is cheapest, Vapi, Retell AI, or Bland AI?
It depends on your stack and volume. Vapi has the lowest published rate ($0.05/min) but the highest number of separate bills; Bland is the most predictable single number but starts higher ($0.09-$0.14/min). At high volume with a tuned budget stack, Vapi or Retell can undercut Bland; at low volume without an engineering team, Bland's flat rate is easier to reason about.
Do I need a developer to use these platforms?
Yes, for all three. Vapi and Retell are both developer-first, API-driven platforms. Bland is closer to plug-and-play but still expects you to configure calls through its dashboard or API — none of the three is a no-code tool for non-technical teams.
Can I switch between Vapi, Retell AI and Bland AI later?
Technically yes, but expect rework. Each platform has its own way of wiring in the LLM, voice and call logic, so migrating means rebuilding your prompt and call flow rather than a simple export/import.