The best AI voice agent platforms for answering business calls
GreetKeeper is our product, and it ranks first for businesses that want a working phone agent without writing code. You forward your number, point it at your website, correct the draft and it answers. Booking, transfers and a signed webhook come with every plan from $49 for 200 calls.
The phrase covers two different purchases. Ready-to-run agents like GreetKeeper, Rosie, Goodcall, Dialzara and Slang.ai are sold to the business that takes the calls. Developer platforms like Vapi, Retell, Bland and Synthflow are sold to teams building their own voice product, and they bill by the minute.
Among the ready-to-run agents, Rosie starts at $49 for 250 minutes with booking on its $149 plan, and Goodcall at $79 for 100 unique customers. Dialzara is $29 for 60 minutes. Slang.ai prices restaurants per location from $399.
Smith.ai adds a trained human team behind its AI from $150 for Pro, for a business that wants people in reserve.
How this was put together
Disclosure: GreetKeeper is our product. We compared agents in September 2026 for a business that wants its own inbound calls answered, not a product to resell. Rival prices come from each vendor's own pricing page that month. Developer platforms are described below, not ranked, because they answer a different buyer.
What we compared
- Whether a business can get an agent answering real calls with no code written.
- What the published price includes: booking, transfers, a phone number.
- The billing unit, and how a long call is charged.
- Whether call data leaves as a signed, structured event you can build on.
- Whether the overage rate is printed.
The shortlist at a glance
Billing unit first, because it decides more of the final bill than the headline price does.
| Charges by | Entry plan | After the allowance | |
|---|---|---|---|
| GreetKeeper | per answered call | $49/mo for 200 answered calls | $0.45 a call on Starter, published |
| Rosie | per minute | Professional $49/mo for 250 minutes | Not published |
| Goodcall | per unique caller | Starter $79/mo ($66 annual) for 100 unique customers | $0.50 per additional unique customer, published |
| Dialzara | per minute | Business Lite $29/mo for 60 minutes | Published on every tier, from $0.48 a minute down to $0.35 |
| Slang.ai | per location | Core from $399/mo per location | No call or minute volumes published at any tier |
| Smith.ai | per call | Free tier at $0 for 25 calls, then $3.00 a call | Published, and the per-call rate falls as the tier rises |
Read from each vendor's own pricing page in September 2026.
GreetKeeper
A working phone agent without code, and a signed webhook for whatever you build next.
Worth it for: A business that wants inbound calls answered and booked now, with call events sent to its own systems as signed JSON.
Charges per answered call. Entry plan $49/mo for 200 answered calls. After the allowance: $0.45 a call on Starter, published.
Rosie
A ready-made agent at the $49 anchor price.
Worth it for: A small business with short calls that wants an agent answering for $49 with 250 minutes.
Not for: Booking on the entry plan, since booking and live transfer sit on the $149 Scale tier.
Charges per minute. Entry plan Professional $49/mo for 250 minutes. After the allowance: Not published.
Goodcall
A ready-made agent billed per unique customer.
Worth it for: Home services and trades with repeat callers, since each customer counts once and minutes are uncapped.
Not for: A business running many numbers, since each phone number is a priced agent.
Charges per unique caller. Entry plan Starter $79/mo ($66 annual) for 100 unique customers. After the allowance: $0.50 per additional unique customer, published.
Dialzara
The lowest entry price among ready-made agents.
Worth it for: Testing an AI phone agent at $29 for 60 minutes, with overage printed on every tier.
Not for: Long or frequent calls, since the meter runs from $0.48 a minute past the first plan's 60.
Charges per minute. Entry plan Business Lite $29/mo for 60 minutes. After the allowance: Published on every tier, from $0.48 a minute down to $0.35.
Slang.ai
A restaurant-only agent priced per location.
Worth it for: A restaurant group that wants a phone agent built for restaurants, from $399 per location.
Not for: Anything outside restaurants, and anyone who wants call volumes on the price list, since none are published at any tier.
Charges per location. Entry plan Core from $399/mo per location. After the allowance: No call or minute volumes published at any tier.
Smith.ai
An AI agent with a human team in reserve.
Worth it for: A law or professional firm that wants trained people behind the agent, at about $2.00 a call on the $150 Pro plan.
Not for: Volume on a budget, since calls past the free tier's 25 cost $3.00 each.
Charges per call. Entry plan Free tier at $0 for 25 calls, then $3.00 a call. After the allowance: Published, and the per-call rate falls as the tier rises.
Ready-made agent or developer platform
Pick by who will own the agent. A developer platform such as Vapi, Retell or Bland gives your engineers the parts to design a voice product. They bill by the minute. Synthflow publishes only an enterprise figure. That route suits a software company shipping voice to its own customers.
If you're the business taking the calls, a ready-made agent skips the engineering project. GreetKeeper drafts its setup from your website and gives you a dedicated local number. It answers every call forwarded to it, in any of the four carrier forwarding modes.
Builders still get a clean feed. GreetKeeper sends one JSON POST per event (call.completed, booking.created, message.taken and transfer.made) to a URL you set. Each is signed with an HMAC-SHA256 header and retried with backoff on a non-2xx response.
Our own pricing, in full
Including the rate after the allowance, which is the number most of this list leaves off.
| Plan | Monthly | Calls included | After that |
|---|---|---|---|
| StarterFor a single location taking calls one line at a time. | $49 | 200 | $0.45 per call |
| ProfessionalBooking, routing and transfers included, not an add-on. | $149 | 750 | $0.35 per call |
| ScaleFor busy phones and longer opening hours. | $349 | 2,000 | $0.25 per call |
The short version
- Booking is included on every tier. Rosie keeps booking and live transfer behind its $149 plan.
- The overage rate is on the pricing page. Rosie, Ruby, Slang and AnswerConnect do not publish theirs.
- Calls are counted, not minutes, so a long useful conversation costs the same as a short one.
Questions people ask about this list
What is an AI voice agent platform?
An AI voice agent platform runs software that holds phone conversations. Ready-made agents such as GreetKeeper answer a business's own calls from $49 a month. Developer platforms such as Vapi, Retell and Bland give engineers the parts to build a voice product and bill by the minute.
Do I need a developer to set up an AI phone agent?
Not for GreetKeeper. Point it at your website for a first draft of your hours, services and FAQs, correct it, and forward your number. Every plan starts with a 14-day free trial with every feature on and no card.
Can I send call data from GreetKeeper to my own app?
Yes. A signed webhook fires after each call, booking, message or transfer. The payload carries the caller's details, the reason for calling, the summary, the intake answers, the booked time and a link to the transcript.
Why aren't Vapi, Retell and Bland in the ranking?
They're sold to teams building a voice product, so their buyer is different from a business that wants its own calls answered. Ranking them on booking or included numbers would compare a finished receptionist with a toolkit.
Hear one of these handle your own call
Your scenario, your greeting, a couple of minutes.