CentriWebRetell AI alternatives fall into four groups: other developer platforms (such as Vapi, Bland AI and ElevenLabs Agents), enterprise builders sold on contract (such as Synthflow), voice AI built into a CRM (such as GoHighLevel), and done-for-you services that charge per call. The right group depends on who will build and maintain the agent, how many calls you take, and whether you want to pay per minute, per call or under a contract.
Picking the group first saves a lot of time, because products inside a group are more alike than products across groups. CentriWeb builds and looks after voice agents for clients, on platforms of this kind, so weigh our view with that in mind. All product facts below come from each vendor’s own pages as at November 2026; check their pages for current prices.
Where Retell AI sits
For reference, Retell’s pricing page lists pay as you go voice agents at $0.07 to $0.31 a minute, with $10 of free credit, 20 included concurrent calls and no minimums. Its homepage describes a no-code studio for customer service teams that developers extend with APIs. That makes it a developer platform with a friendlier front end. You may be looking for an alternative because you want more control, less to manage, a fixed price, or something inside the CRM you already use.
Retell AI alternatives grouped by type
| Type | Examples | How it charges | Who maintains it | Who it suits |
|---|---|---|---|---|
| Developer platform | Vapi, Bland AI, ElevenLabs Agents | Per minute, sometimes plus a monthly fee | A developer, yours or hired | Teams with technical help and specific needs |
| Enterprise builder | Synthflow | Annual contract, quoted | Your team, with vendor launch support | Contact centres and multi-site brands |
| CRM add-on | GoHighLevel Voice AI | Usage-based on top of the CRM subscription | Whoever runs your CRM | Businesses already living in that CRM |
| Done-for-you service | Smith.ai AI Receptionist | Per call, monthly plans | The provider | Owners who want answered calls, not a project |
Developer platforms
These give you the most control and the most to look after.
Vapi
Vapi describes itself as the developer platform for building voice AI agents. Its pricing page lists $0.05 a minute for hosting, with transcriber, model and voice costs passed through at cost, and a $29 a month Core package. Entry concurrency is 4 calls. It suits a developer who wants to pick each component. Our comparison of Retell AI and Vapi covers the two side by side.
Bland AI
Bland’s pricing page lists $0.14 a talk minute on its Start plan, covering the model and voice, with 10 concurrent calls and a cap of 100 calls a day. Its Build plan is $0.12 a minute plus $299 a month, with higher caps. Its homepage focuses on regulated industries and high volumes, inbound and outbound.
ElevenLabs Agents
ElevenLabs’ documentation says its agents can be set up through a developer toolkit, a dashboard or a visual workflow builder, and deployed over telephony through a SIP trunk or a native Twilio integration. It says the platform is aimed at developers and enterprises building at scale. Its API pricing page lists the agent speech engine at $0.08 a minute, with concurrency limits from 4 to 40 depending on tier.
Enterprise builders
Synthflow’s pricing page says every new deployment starts on an annual enterprise agreement, with no free plan, no trial and no per-minute rate. Its documentation lists three ways to build: a no-code Prompt Builder, a low-code Flow Designer and a Platform API. It names contact centres, outsourced call teams and multi-location brands as its market.
This group suits a business with high call volumes and a phone system that needs integrating, where a scoped contract and launch support are worth more than starting small. Our guide to Retell AI vs Synthflow goes further.
Voice AI inside your CRM
If your business already runs on a CRM with its own voice agent, the agent can read and write contact records without a separate integration. GoHighLevel’s help article says its Voice AI agents can answer calls, place outbound calls, book appointments, update or create contacts, and trigger workflows during and after a call. It also says Voice AI only works on accounts using LC Phone or Twilio numbers. GoHighLevel’s pricing page marks Voice AI as having usage-based charges; check that page for the current rates.
CentriWeb builds many client systems on GoHighLevel. The CRM add-on route suits a business whose calendar, pipeline and follow-up already live there. It suits less well if your bookings live in separate practice or job software. Our guide to GoHighLevel Voice AI against a custom voice agent covers where each fits.
Done-for-you services
Some providers sell answered calls rather than a platform. Smith.ai’s AI Receptionist pricing page lists a free plan with 25 calls a month and $3.00 a call after that, and a Pro plan from $150 a month that includes 75 calls. On Pro and Enterprise, calls can be transferred to a live North America-based receptionist.
Paying per call is easier to budget than per minute, and nobody on your team builds anything. The trade-off is less control over how the agent behaves and what it connects to. Check what counts as a call, how spam is treated, and how bookings reach your calendar.
How to choose between the groups
- Who will maintain it? No one technical points to a CRM add-on or a done-for-you service. A developer opens up the platforms.
- How many calls, and how bunched? Check concurrency and daily caps against your busiest hour.
- Where do bookings and customer records live? The agent must write there, or staff will re-key everything.
- Which country is your number in? Several platforms sell only US or North American numbers, so Australian and New Zealand businesses usually bring a number through a carrier.
- How do you want to pay? Per minute, per call, or under a contract.
Test before you switch
Feature lists look similar across the groups, so the only reliable comparison is a test with your own calls. Most of the self-serve options above start with free credit or a free plan. Use it like this:
- Pick three real calls from the last month: a simple question, a booking, and an awkward one, such as a caller outside your service area or after a price you don’t publish.
- Build the same short agent on each option you’re weighing, with the same opening, the same facts and the same booking rule.
- Call it from a mobile in a car or a noisy room. Interrupt it. Change your mind halfway through a booking.
- Check where the result lands. The booking should appear in the calendar your team uses, and the caller’s details should reach the CRM without anyone re-typing them.
- Read the transcript and list what you’d need to fix. That list is a fair guide to the monthly upkeep.
- Price a full month on each pricing page using your own minutes or calls, including your busiest week.
For a builder, the awkward call might be a homeowner asking whether you build on their land or in their suburb, which is the kind of question our page for builders and construction businesses looks at. For a clinic or a trade it will be something else. Use whatever your front desk dreads.
When a built and looked after system fits better
A self-serve platform or a done-for-you service is enough when call volume is low, the owner has time and interest to run it, or a standard plan does the job. Many small businesses are in that position.
A system built and looked after for you fits when calls carry real money, the agent must book into the real calendar and write to the CRM every time, and nobody wants to own the prompts and integrations. That is what our AI voice agent service does, on whichever platform suits the calls.