Vapi vs Retell AI vs Bland AI: which voice agent platform?

Vapi, Retell AI and Bland AI are the three names that come up most when a business wants an AI agent to answer or make phone calls. All three can hold a natural conversation, book appointments and hand a call to a person. They differ in who they are built for, how the bill is put together, and how much work it takes to go live.

We build voice agents for clients on these platforms. This is the honest comparison we wish we had when we started.

Which one should you pick?

How each one bills you

Every AI phone call has the same parts: speech-to-text (hearing the caller), a language model (deciding what to say), text-to-speech (the voice) and telephony (the phone line). The platforms package these differently.

• Retell charges per minute for each part: $0.055 for its voice engine, $0.015 for most voices, the model of your choice (for example $0.064 for Claude 5 Sonnet or GPT 5.6 Terra, less for smaller models), and $0.015 for telephony. There is no platform fee, and 20 concurrent calls are included.
• Vapi charges a $0.05 per minute hosting fee, then passes through each provider at cost: transcription around $0.01, the model from under $0.01 to about $0.045, the voice around $0.015 to $0.024, and telephony (for example Twilio inbound $0.008). A $29 a month Core plan raises limits to 10 concurrent calls.
• Bland charges one flat talk rate: $0.14 per minute on the free Start plan, or $0.12 per minute on Build, which costs $299 a month. Telephony is billed separately at cost unless you bring your own.

Pricing side by side

Sources: Retell pricing, Vapi pricing, Bland pricing. Rates change often, so check the live pages before you commit.

Retell AI: the fastest path to a working agent

Retell's builder lets you set up the conversation as a flow or a single prompt, test it in the browser, attach a phone number and go live. Its per-minute pricing is spelled out line by line, and the page has a calculator, so you can predict your bill before you build.

Where it shines

• Quick to build and test, even without a developer
• 20 concurrent calls included on pay as you go, which covers most small businesses
• Billing to the second, and no charge for failed calls
• Knowledge bases, denoising, guardrails and PII removal as small per-minute add-ons

Where it hurts

• Premium voices and larger models raise the rate quickly (some voices cost $0.08 to $0.10 a minute)
• Billing continues through silence and hold time
• Enterprise features such as SSO and HIPAA need a custom contract

Best for: clinics, home services, agencies and any business that wants a receptionist, booking or lead qualification agent live within days.

Vapi: the developer's toolkit

Vapi is built for teams that want to choose every piece: which transcriber, which model, which voice, which phone carrier. It has a strong API, tools for calling your own systems mid-call, and works over phone, web and WebSockets.

Where it shines

• The most control over models, voices and call logic
• Providers billed at cost, so you can tune the price per minute
• Free web and SIP transport, and cheap carriers such as Telnyx at $0.0055 a minute

Where it hurts

• More moving parts, so it takes more time to build and debug
• Low default limits: 4 concurrent calls until you pay for Core or extra lines
• Support plans with service levels start at $999 a month

Best for: software teams and agencies building custom voice products, or businesses with unusual call flows and a developer on hand.

Bland AI: one simple rate for high volume

Bland keeps pricing simple: one talk rate per minute covers the AI, and you pay the phone line on top. The Build plan adds higher limits for daily and hourly calls, which matters for outbound teams calling lists.

Where it shines

• One rate to understand, with no separate model and voice charges
• High call volumes on Build: 50 calls at once and up to 2,000 calls a day
• Bring your own Twilio or SIP to avoid transfer fees

Where it hurts

• The $299 monthly fee only pays off at higher volumes
• The Start plan caps you at 100 calls a day
• SMS and web chat are enterprise features

Best for: sales teams and call centres running outbound campaigns or large inbound volumes.

A worked example: 1,000 minutes a month

Say your agent answers about 300 calls a month averaging just over 3 minutes each, which is roughly 1,000 minutes.

These are our estimates from the published rates, not quotes. At this volume the three are close, and Bland's Build plan only makes sense at several thousand minutes a month. What changes the total far more is design: an agent that resolves calls in 2 minutes instead of 4 halves the bill on every platform.

Common mistakes

• Choosing on minute price alone. Build time, testing and fixing edge cases cost more than the difference in rates.
• Picking the biggest model by default. Many receptionist calls run well on a faster, cheaper model. Test before you pay for the top tier.
• No plan for the hand-off. Decide when the agent transfers to a person and what it says first, or callers get stuck.
• Skipping calling rules. Outbound AI calls in the US are covered by consent rules. Read our calling compliance guide before you dial a list.
• Never listening to calls. Review recordings weekly for the first month. That is where the real fixes come from.

FAQ

Which is cheapest per minute?

At typical settings Vapi can be the cheapest because each provider is billed at cost and you can pick budget models and carriers. Retell is close and simpler to predict. Bland's flat rate is easy to understand but usually a little higher unless you are on the Build plan at volume.

Can these agents book appointments into my calendar?

Yes. All three can call tools during a conversation, such as checking availability and booking a slot in Google Calendar, Calendly or your CRM. The quality depends on how well the agent and its tools are set up and tested.

Will callers know they are talking to AI?

Modern voices sound natural, but you should still tell callers they are speaking with an AI assistant. It builds trust, and some laws and platforms require it, especially for outbound calls.

Do I need a developer?

For Retell and Bland, a simple receptionist can be built without code. Vapi, and any agent that connects to your own systems, goes much faster with a developer or an agency.

Can I switch platforms later?

Yes. The prompts, call flows and integrations carry over in spirit, but you rebuild them on the new platform. Keep your prompt and call flow documented so a move is quick.

Final verdict

For most small businesses we start with Retell: it is quick to build, the price is clear, and the included concurrency covers real call volumes. Choose Vapi when you have a developer and want to tune every part of the call. Choose Bland when you run high-volume outbound and the flat rate and limits suit your campaigns.

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