Trying to decode Synthflow AI pricing before signing up? Fair enough.
In this guide, we break down every cost component in the Synthflow AI pricing structure such as what's included, what costs extra, and how it compares to alternatives like Zeeg, which bundles AI voice agents natively into its scheduling CRM.
What is Synthflow AI?
Before getting into the numbers, here’s a quick reminder of what you're actually buying. Synthflow AI is a no-code platform for building and deploying AI voice agents which are conversational AI phone bots that handle inbound and outbound calls on your behalf. The pitch is pretty simple. You get an AI that picks up the phone, understands what the caller wants, and takes action without anyone on your team having to lift a finger.
The platform is built around accessibility. You configure agent behavior through prompts, connect a phone number, set up your integrations, and you're live with no coding required. It's aimed at sales teams, small businesses, and agencies that want to automate call handling without building infrastructure from scratch.
One thing worth flagging upfront is that Synthflow is mainly a voice AI layer. It handles the conversation side well, but for the full workflow (CRM logging, calendar booking, follow-up automation) you'll usually need to connect it to other tools. That's a deliberate design choice, and it has real implications for the total cost of running it. We'll get there.
How Synthflow AI's pricing works
Synthflow has dropped the traditional tiered plan structure in favor of a pure pay-as-you-go model, with a separate Enterprise option for high-volume teams. There's no fixed monthly fee to get started. Instead, you pay based on what you use, and your bill is the sum of several individual cost components.
That makes the Synthflow AI pricing model more flexible than a flat subscription, but also harder to estimate upfront. The best way to understand it is to work through each component one by one, which is exactly what we'll do below.
Synthflow AI pricing: Full plan comparison
Here's the whole picture in one place:
Breaking down the costs of Synthflow AI
The voice engine
Every call you run through Synthflow starts with the voice engine cost: $0.09 per minute. This covers the AI's ability to listen, process speech, and generate a spoken response in real time. It applies to both inbound and outbound calls, and it's the one cost component that's always present regardless of any other configuration choices you make.
LLM costs
On top of the voice engine, you're also paying for the large language model (LLM) that powers your agent's reasoning; how it understands what the caller is saying and decides what to say back, that is. Synthflow gives you a choice of models, each with its own per-minute rate:
- GPT-4.1 mini — $0.02/min. The most cost-efficient option, and perfectly capable for simple call flows like appointment scheduling or basic lead qualification.
- GPT-5, GPT-5.1, GPT-5.2 — $0.04/min. A solid middle ground between cost and capability.
- GPT-4.1 — $0.05/min. The most capable option at the highest per-minute rate, best suited for complex or unpredictable conversations.
- Bring Your Own LLM. Available if you already have your own model setup and want to use it instead.
The model choice matters more than it might seem. For a simple agent that follows a predictable booking script, GPT-4.1 mini is the right call. For agents handling objections, nuanced qualification questions, or conversations that can go in many directions, a more capable model will genuinely perform better, just at a higher cost per minute.
Telephony costs
Getting calls into and out of the platform has its own cost too, with a few options:
- Synthflow-managed Twilio — $0.02/min. Synthflow handles the Twilio account on your behalf. This is the default for most pay-as-you-go users.
- Bring Your Own Twilio (BYO) — $0.00/min. If you already have a Twilio account, you can connect it directly and skip this cost entirely. Your Twilio account will still be billed separately by Twilio, but it removes this line item from your Synthflow bill.
- Synthflow Native Telephony. Available on Enterprise only, but more on that shortly.
What a typical call actually costs
Putting those three components together, here's what a single minute of call time costs at different configurations:
To put that in real terms, a typical 5-minute inbound call on the standard setup will cost you roughly $0.65. Run 500 of those in a month (not unusual for a busy business) and you're looking at $325 in call costs alone, before any add-ons.
Synthflow AI modular pricing: The add-ons
With the base costs covered, the next layer is optional add-ons. This is where Synthflow AI's modular pricing model really comes into play. You can keep things lean and skip all of these, or layer them on based on what your operation actually needs.
Performance Routing — $0.04/min. This optimizes how calls are routed for better connection quality and lower latency. For most standard use cases it's optional, but for sales teams where call quality is non-negotiable, it's worth considering.
Global Low Latency Edge — $0.04/min. Designed to bring call latency below 600 milliseconds, making conversations feel more natural and responsive. Again, optional, but you'll notice it when the calls demand it.
Extra concurrency — $20/slot/month. The pay-as-you-go plan includes 5 concurrent calls by default, meaning 5 calls can run at the same time. Need more? You can add slots at $20 each, up to 50 additional slots. This becomes relevant quickly for high-volume inbound operations or outbound campaigns running at scale.
Phone number — $1.50/month. A dedicated phone number through Synthflow is $1.50/month, which is pretty straightforward and reasonably priced. If you'd rather use your existing business number, the BYO Twilio option handles that without this cost.
White Label & Reseller Toolkit — $2,000/month. This one is clearly aimed at agencies building AI calling products for multiple clients. It includes custom domain, white-label branding, and sub-account management infrastructure. Not relevant for most individual businesses, but significant if you're building a reseller operation.
What's included in the pay-as-you-go plan
Before moving on to Enterprise, it's worth being clear about what every pay-as-you-go user gets without paying extra. The base plan includes:
- Unlimited AI agents
- 5 concurrent calls (expandable with add-ons)
- Full API access and integrations
- Widget and simulation tools
- SMS and WhatsApp support (billed as 5 messages = 1 minute of voice usage)
- Synthflow Academy training resources
- Support via ticketing system
- GDPR and SOC2 compliance
The unlimited agents inclusion is particularly worth noting. You're not paying per agent or per workspace, so building multiple agents for different teams, use cases, or departments doesn't cost extra. That's a meaningful advantage for businesses with varied call flows.
The Enterprise plan
Once you move past 10,000 minutes of calls per month, the pay-as-you-go model starts to make less sense economically, and Synthflow's Enterprise plan is built for that level of scale. Pricing is custom (you'll need to contact their sales team) but here's what you're getting for the conversation:
- Synthflow Native Telephony (unavailable on PAYG)
- Unlimited concurrent calls
- Custom API rate limits with priority routing
- 99.99% uptime guarantee with a formal SLA
- HIPAA compliance
- Advanced compliance: MSA support, geo-based sub-processing, on-premise multi-region deployment, and flexible hosting options
- Dedicated Slack support channel
- Early access to new features
- Assigned Solution Architect and Customer Support Manager
- Full enterprise onboarding and training
- White Label & Reseller Toolkit included (no $2,000/month add-on needed)
A few things stand out here. The uptime SLA is genuinely important for businesses where downtime translates directly to missed calls and lost revenue, and it's something pay-as-you-go users simply don't get. HIPAA compliance opens the door to healthcare use cases that aren't possible on the PAYG plan. And the advanced hosting flexibility (including geo-based sub-processing and on-premise options) matters significantly for regulated industries or organizations with strict data residency requirements.
What Synthflow doesn't include
This is the part that catches a lot of new users off guard, so it's worth being direct about. Synthflow's pricing covers the voice AI layer, which is the calling engine itself. A complete AI receptionist workflow, though, usually needs more than that, and those additional pieces have their own costs.
A booking tool. Synthflow has no native calendar booking. To actually schedule a meeting at the end of a call, you'll need a connected scheduling tool like Calendly, Cal.com, or similar. If you don't already have one, that's an extra $10–20/month.
A CRM. Call data is stored in Synthflow's dashboard, but if you want it feeding into HubSpot, Salesforce, or GoHighLevel, you'll need active subscriptions to those platforms and the integrations configured. Depending on which CRM you're on, that cost can range from modest to significant.
Automation middleware. For more complex workflows (routing call outcomes to different tools, triggering follow-up sequences, syncing data across platforms) many Synthflow users rely on Zapier or Make as the connective tissue. Both charge separately, usually $20–50/month depending on task volume.
None of this is hidden, exactly. But the "free to start" framing can create a misleading impression of what it actually costs to run a complete workflow. The honest picture for a business starting from scratch is a monthly bill that's meaningfully higher than the call costs alone.
Is Synthflow AI pricing worth it?
For the right use case, genuinely yes. The pay-as-you-go structure works especially well for:
- Businesses with variable or seasonal call volumes, where a fixed monthly fee for unused minutes doesn't make financial sense
- Developers and agencies testing the platform before scaling up
- Operations with modest call volumes where the per-minute costs stay manageable
Where it gets harder to justify is the mid-range scenario: a business handling a few hundred calls per month that also needs to invest in a CRM, a booking tool, and automation middleware on top of Synthflow itself. By the time all those pieces are in place, a realistic monthly spend can land between $200–400 before you're anywhere near enterprise volume.
That said, perspective matters here. A full-time receptionist in the US costs roughly $2,500–3,750 per month in salary alone, not counting benefits or management overhead. Even at $300/month for the full AI stack, the math still works strongly in favor of automation. The more relevant comparison is against other AI calling platforms and against solutions that bundle more of the workflow under a single subscription.
How Synthflow compares to other AI voice platforms
The voice AI market has filled up quickly, and Synthflow sits in a competitive field. A few of its main rivals worth knowing:
Bland AI runs on a similar consumption-based model, with inbound rates around $0.09/min for the base voice layer. LLM and telephony are billed separately as well, so total per-minute costs land in a comparable range to Synthflow.
Retell AI prices around $0.07–0.10/min depending on configuration, which slightly cheaper at the base level, though it's more developer-oriented and less accessible for non-technical users building their first agent.
VAPI is the most developer-focused option in the group. Highly customizable, with competitive per-minute rates, but genuinely not a no-code platform. If you're comfortable with APIs and want full control, VAPI delivers that depth, though the setup curve is real for anyone who isn't technical.
Where Synthflow holds its own is in the combination of a no-code interface, a wide integration library, and proper white-label capabilities for agencies. Its per-minute rates aren't the lowest in the market, especially once LLM and telephony stack on top of the base voice cost, but for non-developers who need something production-ready without writing code, it's one of the more accessible options available.
Zeeg: When you want everything in one place
At this point it's worth stepping back and asking what most businesses are actually trying to accomplish with a voice AI tool. For the majority, the goal is the same: answer calls, qualify the caller, book a meeting. Synthflow gets you there, but it requires assembling several tools to do it. Zeeg approaches that same goal differently.
Zeeg is a scheduling CRM with AI voice agents built directly into the platform. One subscription covers the voice agent, the booking system, and the CRM. There's no Zapier in between, no separate calendar integration to configure, and no question about where call data ends up as it all lives in the same system from the moment the phone rings.
What Zeeg's AI agents do
Zeeg AI Agents handle both inbound and outbound calls through a real back-and-forth conversation, not an IVR press-1 phone tree. The agent listens, understands the caller's intent, collects their details (name, email, company, and any custom fields) applies your routing rules, and books the right meeting directly into the calendar. The transcript, caller profile, and booking outcome all land automatically in the Zeeg CRM with no manual steps or integrations required.
Setup runs through a plain-text prompt builder. You describe how the agent should behave, choose from pre-built templates (Appointment Booker, Sales Qualifier, Support Callback), set the language and voice, define routing rules in plain language, and test it from your browser before going live. The whole setup can realistically be done in under an hour.
Zeeg's pricing
Zeeg's plans cover scheduling, CRM, and AI agents under a single subscription:
Starter — Free forever. A solid entry point for solo users who want to explore the platform without a credit card.
Professional — $10/user/month (billed annually) or $12/month billed monthly. AI agents are available from this plan onwards, along with advanced scheduling, multiple calendar connections, and custom branding.
Business — $16/user/month (billed annually) or $20/month billed monthly. Adds team scheduling, round-robin distribution, routing forms, and analytics — the right tier for teams that need collaborative scheduling plus AI calling.
Scale — $30/user/month (billed annually) or $40/month billed monthly. The full-featured option for organizations with higher call volumes and more complex routing needs.
Voice minutes work on a transparent credit model — every call shows its exact cost in the CRM, with no surprises at the end of the month. Inbound calls run approximately €0.07/min, outbound around €0.19/min, with volume bundles available:
Zeeg vs. Synthflow
If you already have a CRM and booking stack and just need a voice AI layer on top, Synthflow slots in well. If you're building from scratch (or want one predictable bill instead of several variable ones), Zeeg's integrated model may be a cleaner, simpler fit.
The verdict: Is Synthflow AI pricing right for your business?
Synthflow's move to a pure usage-based model is genuinely well-suited for a certain kind of user, especially those with variable call volumes, developers testing before scaling, or agencies that want the white-label flexibility without a fixed monthly commitment. The unlimited agents inclusion is generous, and the ability to choose your own LLM and telephony gives you real levers to control cost.
The complexity is real, though. Your actual monthly spend is voice engine + LLM + telephony + add-ons + whatever supporting tools you connect on top. For businesses building the full stack from scratch, "free to start" can turn into $200–400/month faster than the headline pricing suggests.
For teams that want calling, booking, and CRM working together without stitching tools together themselves, Zeeg offers a different answer: one bill, one platform, no integration maintenance. The AI agents are built into the same system that manages your calendar and contact records, which means less setup time and fewer moving parts from day one.
Whichever direction you lean, run the numbers on your realistic call volume before committing. Take a free trial, test your call flows, and make sure the per-minute math actually works for your use case at the scale you're planning to operate.
Synthflow AI pricing: FAQs
How much does Synthflow cost per minute?
The base voice engine costs $0.09/min. On top of that, you pay for your LLM ($0.02–$0.05/min) and telephony ($0.02/min for managed Twilio, or $0.00 with BYO). A typical all-in per-minute cost lands between $0.11 and $0.16/min depending on your configuration.
Is Synthflow AI free?
Free to start, yes. There's no monthly fee to sign up, and you only pay once live calls are running. That said, running a complete workflow will involve costs from connected tools beyond Synthflow itself.
Does Synthflow still have Starter, Pro, Growth, and Agency plans?
No. Those tiers have been discontinued. Synthflow now operates on two tiers only: pay as you go (usage-based, free to start) and Enterprise (for 10,000+ minutes/month, custom pricing).
Can I use my own Twilio account?
Yes. The BYO Twilio option lets you connect an existing Twilio account and avoid the $0.02/min managed telephony cost on the Synthflow side. Your Twilio account will still bill you separately for usage.
Can I white-label Synthflow on the pay-as-you-go plan?
Yes, but it's an add-on at $2,000/month. On the Enterprise plan, white-label and the reseller toolkit come included.
How does concurrency work?
The pay-as-you-go plan includes 5 simultaneous calls. Additional slots cost $20/month each, up to 50 extra. Enterprise users get unlimited concurrency.
Am I charged for failed calls?
No. Synthflow doesn't charge for calls that fail to connect. Billing applies only to connected call minutes.
Is Synthflow HIPAA compliant?
HIPAA compliance is available on the Enterprise plan only. If you're in healthcare or dealing with protected health information, the pay-as-you-go plan won't cover that requirement.
How does Synthflow bill for SMS and WhatsApp?
Text channel usage is billed on a minute-equivalent basis: 5 messages sent or received equals 1 minute of voice usage in billing terms.
