Synthflow AI Receptionist starts at $29 per month, with tiered plans that include a fixed bundle of call minutes and features like AI voice agents, real-time scheduling, custom workflows, and integrations (HubSpot CRM, Google Calendar, Zapier, etc.). The pricing follows a clear usage-based model – each plan comes with a monthly minute allotment and per-minute overage fees if you go beyond that, which can help teams predict costs as they automate call handling and lead management.
For businesses that prefer unlimited call minutes and simpler flat pricing, alternatives such as Welco.ai take a different approach (flat monthly fee for fully autonomous AI reception with no per-minute billing).
This guide breaks down Synthflow’s pricing structure, plan features, and user feedback to help you evaluate whether it fits your business needs – and how it stacks up against Welco and other AI receptionist tools.
What is SynthflowAI Receptionist?
Synthflow AI Receptionist is a no-code, AI-powered voice platform that automates incoming business calls using advanced conversational AI and natural language understanding. It essentially acts as a 24/7 AI receptionist that can answer calls, understand caller intent in real time, qualify leads, capture customer information, schedule appointments, and route calls to the right person or department – all without human intervention.Learn more about what an AI receptionist is and how it works.
It’s powered by enterprise-grade voice AI with extremely low latency (in-house telephony infrastructure delivers sub-100 ms response times for voice interactions), enabling natural, human-like conversations.
Key Features of SynthFlow AI Receptionist
| Features | Description |
|---|---|
| Natural Language Conversational AI | Understands caller intent contextually and responds with human-like dialogue. Handles interruptions, clarifications, and keeps conversations natural rather than robotic – delivering the kind of personalized automated customer interactions that modern callers expect. |
| Intelligent Call Routing & Transfers | Automatically routes calls based on caller intent, department, or custom business rules. Can transfer calls to live staff when needed, with intelligent call transfer capabilities |
| Appointment Scheduling & Lead Qualification | Integrates with calendar systems (e.g. Google Calendar via Zapier) to book appointments in real time during calls. Conversationally qualifies leads and captures information (like name, email, inquiry details) through smart intake forms without requiring manual data entry. |
| No-Code Builder & Custom Workflows | Offers a visual drag-and-drop Flow Studio to customize call workflows without code. Users can define greetings, question/answer logic, and actions (sending SMS, updating CRM, etc.) with no technical expertise needed. |
Enterprise-Grade Performance
Synthflow’s enterprise-grade voice AI technology delivers industry-leading performance across key metrics:
| Performance Metric | Details |
|---|---|
| Voice Latency | Sub-100ms round-trip response times on par with human conversation speed, meaning callers don’t experience awkward pauses |
| AI Technology Stack | Uses Deepgram for transcription and GPT-4o for language understanding, providing end-to-end call handling with built-in telephony and speech recognition |
| Uptime & Reliability | 99.9%+ uptime backed by global infrastructure designed for continuous availability |
| Proven Scale | 45 million+ calls handled by 2025 with consistent uptime, demonstrating enterprise-ready stability |
In summary, Synthflow AI Receptionist is a robust solution for automated call handling. It eliminates missed calls and manual call routing by using AI to greet callers, understand their needs, and take appropriate actions in real time. With no coding required to set up sophisticated voice agents, even non-technical teams can.
How Much Does Synthflow AI Receptionist Cost?
Synthflow AI Receptionist pricing starts at $29 per month for the Starter plan and scales up to custom enterprise pricing for high-volume users. Each plan includes a bundle of call minutes per month, along with core voice automation features (AI voice agents, real-time booking, workflow customization, and integrations via its API and Zapier).If you exceed the included minutes, overage is charged at a small per-minute rate. Synthflow offers a 14-day free trial (for higher-tier plans) so businesses can test the platform, although note that the free trial is limited to about 15 minutes of call time for testing.
Pricing Structure
- No hidden setup fees or long-term contracts – Plans are month-to-month
- Upgrade or downgrade as needed – Changes take effect immediately for upgrades or at the next billing cycle for downgrades
- Annual billing options available – Provides significant discounts (roughly 15–17% off, equating to two months free)
Synthflow Pricing Plans Overview
Synthflow offers five main pricing tiers — Starter, Pro, Growth, Agency, and Enterprise — to accommodate businesses at different stages of growth and call volume needs. All plans are billed monthly by default (with discounts for annual prepayment) and include the essential voice AI features.
| Plan | Monthly Price | Annual Price | Included Minutes | Overage Rate | Concurrent Calls | Best For |
| Starter | $29 | N/A | 50 minutes | No overage* | 5 | Developers, startups, or small businesses experimenting with AI voice automation |
| Pro | $450 | ~$375 | 2,000 minutes (~33 hours) | $0.13/min | 25 | Small teams managing low to moderate call volumes |
| Growth | $900 | ~$750 | 4,000 minutes (~66 hours) | $0.12/min | 50 | Scaling teams and service companies with higher call traffic |
| Agency | $1,400 | ~$1,250 | 6,000 minutes (~100 hours) | $0.12/min | 80 | Agencies and large resellers managing multiple client accounts |
| Enterprise | Custom | Custom | Custom volume | As low as $0.08/min | 200+ | Large enterprises with very high call volumes or specialized compliance needs |
Note: The Starter plan has no overage charges; you would need to upgrade if you consistently need more than 50 minutes.
Key Features by Plan
| Feature | Starter | Pro | Growth | Agency | Enterprise |
| AI Assistants | Unlimited | Unlimited | Unlimited | Unlimited | Unlimited |
| Voice API Access | ✓ | ✓ | ✓ | ✓ | ✓ |
| Basic Integrations | ✓ | ✓ | ✓ | ✓ | ✓ |
| Workflow Builder | ✗ | ✓ | ✓ | ✓ | ✓ |
| Team Access | ✗ | ✓ | ✓ | ✓ | ✓ |
| Subaccounts | ✗ | ✗ | 25 | Unlimited | Unlimited |
| Rebilling | ✗ | ✗ | ✓ | ✓ | ✓ |
| White-Label Platform | ✗ | ✗ | ✗ | ✓ | ✓ |
| Beta Features Access | ✗ | ✗ | ✓ | ✓ | ✓ |
| Custom Workflows | Limited | Standard | Standard | 100,000 | Unlimited |
| Support Level | Basic | Standard ticketing | Standard ticketing | 30-day onboarding + Private Slack | Dedicated solutions architects |
| SIP Trunk Integration | ✗ | ✗ | ✗ | ✗ | ✓ |
| Uptime SLA | ✗ | ✗ | ✗ | ✗ | ✓ |
| Custom Integrations | ✗ | ✗ | ✗ | ✗ | ✓ |
Plan Highlights
Starter ($29/month) – Ideal for initial testing or handling a small volume of calls without a large investment. Includes unlimited AI assistants, up to 5 concurrent calls, voice API access, and basic integrations.
Pro ($450/month) – Unlocks the Workflow Builder for custom call logic and Team Access for collaboration. Perfect for growing businesses that want to streamline call handling with a few thousand minutes monthly.
Growth ($900/month) – Adds 25 subaccounts for managing multiple locations or client accounts, rebilling capabilities for agencies, and access to new beta features. Ideal for fast-growing operations and businesses managing multiple locations.
Agency ($1,400/month) – Provides unlimited subaccounts, white-label platform capabilities, 100,000 custom workflows, and enhanced support with a 30-day onboarding program and private Slack channel. Geared towards resellers and agencies managing multiple client brands.Enterprise (Custom Pricing) – Offers the lowest per-minute rates, SIP trunk integration, guaranteed uptime SLA, custom features, 200+ concurrent calls, and dedicated support teams. Designed for large-scale deployments requiring heavy customization and compliance assurances (SOC2, HIPAA, GDPR).
Test Drive AI Reception in Minutes
If you’re exploring Synthflow alternatives, try Welco’s free trial to experience AI call handling without setup stress or minute limits.
Synthflow Customer Reviews & User Feedback
Synthflow has garnered mostly positive ratings from users, with some caveats noted by smaller customers.
Ratings:
- G2: 4.5 out of 5
- Trustpilot: 4.4 out of 5 (based on 200+ reviews)
These strong ratings reflect Synthflow’s solid reputation among startups, developers, and teams deploying voice AI solutions.
What Users Say About Synthflow
Synthflow has garnered mostly positive ratings from users, earning 4.5/5 on G2 and 4.4/5 on Trustpilot (based on 200+ reviews). Here’s what customers appreciate and where they see room for improvement:
What Users Like
- Realistic AI voices & quick setup – Synthflow’s AI voices sound natural and respond quickly during calls, creating a smooth caller experience. The no-code approach allows many users to get an AI receptionist up and running in a short time. One reviewer called it “definitely the best AI caller on the market.”
- Affordable with excellent support – Small businesses appreciate the cost-effective solution with strong ROI. Customer support during onboarding is praised as “life-changing” and helpful, making it easier for lower-tier plan users to get started.
What Users Complain About
- Feature limitations on lower tiers – A recurring criticism is that important features are locked behind the Enterprise plan. Users described feeling “baited” by the low starting price, only to discover they need higher tiers for truly useful call flows. One reviewer noted “half the platform is crippled unless you’re on enterprise.”
- Insufficient trial period – The 14-day trial is limited to ~15 minutes of call time, which many found too restrictive to properly test the platform and fine-tune their AI agent before committing to a paid plan.
- Occasional voice glitches – While generally praised, some voices can stutter or have volume changes. Users advise to “test each one” before deploying. Voice customization is also limited—adjusting tone or speed to match your brand isn’t fully open-ended.
- Billing & cancellation issues – Some users reported difficulty canceling service and unexpected charges, with complaints about “no phone support, no accountability.” Support in these cases was seen as slow or focused on upselling rather than helping.
Bottom line: Synthflow excels for teams willing to invest in Pro or higher plans, offering excellent voice quality and scalability. However, smaller businesses should carefully review which features are included in their chosen tier to avoid unexpected limitations.
Skip the Feature Limitations & Billing Surprises
Try Welco free for 7 days with full features included from day one. No enterprise plan needed.
Synthflow Pricing vs Competitors
Here’s how Synthflow compares with other leading AI receptionist and communication tools in terms of pricing and features:
| Feature | Synthflow | Welco.ai | Retell AI | Vapi |
| Pricing Model | Minute-based tiered + overages | Monthly subscription | Pay-as-you-go (per minute) | Pay-as-you-go (modular pricing) |
| Starting Price | $29/month (50 min) | $39/month | $0.07+/min | $0.05-$0.34/min |
| Free Trial | 14-day | 7-day (real calls) | $10 credits | $10 credits |
| AI Model | No-code, customizable workflows (GPT-4o) | AI-first (GPT-4o, GPT-4o-mini (Default),GPT Realtime, GPT-4o-mini Realtime,GPT-4o Realtime) | Customizable LLMs (GPT-4, Claude, Gemini) | Customizable LLMs (GPT-4, Groq, Mistral) |
| Integrations | Zapier, HubSpot, GoHighLevel, Twilio, Stripe, ElevenLabs | Zapier,HubSpot, Salesforce, Twilio, Calendly, FieldCamp | Twilio, HubSpot, Salesforce, Make, Zapier | SDKs (Web, iOS, Flutter, React), Twilio, Deepgram |
| Language Support | 30+ languages | 20+ languages (auto-detect) | 100+ languages (customizable) | 100+ languages (customizable) |
| Workflow Builder | Drag-and-drop visual no-code | Drag-and-drop interface with a visual node-based workflow builder that lets you connect nodes to create call flows with real-time validation. | Drag-and-drop agent builder | Flow Studio no-code editor |
| Use Case | Teams needing rapid no-code workflows | Businesses prioritizing transparency & simplicity | Developers building custom voice agents | Developers building highly customizable voice AI |
Choose Synthflow if: You need highly customizable AI receptionists and are willing to manage usage-based pricing with potential overage fees. Best for tech-savvy teams comfortable with monitoring minutes and navigating feature limitations on lower tiers.
Choose Welco.ai if: You want the smartest choice for predictable costs and hassle-free operation. With AI-managed calls for a monthly rate, no surprise overage charges, and true “set it and forget it” simplicity, Welco delivers enterprise-quality voice AI without the complexity or hidden costs. Perfect for growing businesses that value transparency, ease of use, and scalability without constantly monitoring usage or upgrading plans.
Choose Retell AI if: You’re a developer building custom voice agents, need maximum API control and ultra-low latency, and are comfortable with technical implementation.Choose Vapi if: You’re a highly technical team wanting to build voice AI from scratch with complete control over the AI stack and custom service composition.
Looking for a SynthflowAI Receptionist Alternative?
If you’re evaluating AI call automation platforms, it’s worth comparing your options beyond just Synthflow. While Synthflow excels at customizable workflows and detailed call automation via its no-code builder, the minute-based pricing model and feature limitations on lower tiers may not suit every business.
For companies that prioritize predictable costs and simplicity, alternatives like Welco.ai offer monthly pricing —no surprise charges. Features like SMS follow-ups, call transfers, and intake forms are included from the start, making it easier to scale without constantly monitoring usage.
The right choice depends on your specific needs:
- Choose Synthflow if you need highly granular workflow customization and have the resources to actively manage a usage-based platform
- Consider alternatives if you want predictable budgeting, unlimited volume, and prefer a “set it and forget it” approach
Each platform has trade-offs. Synthflow offers deep customization but requires more hands-on management. Flat-rate platforms sacrifice some advanced features for simplicity and cost predictability. Evaluate what matters most for your team—workflow flexibility or operational simplicity—before committing to any solution.
Ready for Truly Unlimited AI Reception?
Experience Welco’s set-it-and-forget-it simplicity with 7 days free. Real calls and straightforward pricing—no surprises.
FAQs About Synthflow Pricing & Plans
Does Synthflow charge extra for integrations or API usage?
No – all Synthflow plans include access to its API and standard integrations (like Zapier connectors, CRM integrations, etc.) without extra fees. In other words, you won’t pay additionally just to integrate Synthflow with your other tools; those capabilities are part of the subscription.
However, some advanced integration features are only available on higher tiers – for example, SIP trunking integration (direct connection to your own PBX/phone carrier) is an Enterprise feature, and compliance-related APIs or certain analytics might also require a top plan. But there are no hidden setup or integration fees on any plan. The pricing you pay per month already includes the use of the platform’s APIs, workflow builder, and integrations.
Can I upgrade or downgrade my Synthflow plan at any time?
Yes. Synthflow is a monthly subscription service and you have flexibility to change plans as your needs evolve. You can upgrade at any time, and the change will take effect immediately (your billing will be prorated accordingly). If you need to downgrade to a lower plan, the change will apply from the start of your next billing cycle. There are no penalties for switching plans.
This means if your call volume grows, you might upgrade to the next tier mid-month to get more minutes (or to unlock features); likewise, if you over-provisioned, you can move down next month. Many users appreciate this flexibility, especially given the minute-based model – you aren’t locked into a long-term contract and can adjust month-to-month.
(Do note that canceling requires proper notice via the dashboard to avoid being charged for the next period – as with any subscription service. Some users reported issues when they didn’t cancel correctly, so be sure to follow the official process.)
How is Synthflow different from traditional virtual receptionist services (or answering services)?
The big difference is that Synthflow is entirely AI-driven. Traditional virtual receptionist services (like a third-party call center or a human answering service) involve people handling your calls (sometimes augmented by scripts or basic IVR).
Synthflow’s solution uses conversational AI agents to handle calls start-to-finish without human involvement. This yields a few benefits:
- Calls are answered instantly, 24/7 (AI doesn’t need to sleep or take breaks)
- Cost can be much lower when scaled – Once you pay for the AI platform, handling additional calls has minimal marginal cost. Businesses have reported reducing call handling costs by up to 90% using AI vs. human staff. Learn more about measuring AI receptionist ROI to understand the full cost impact.
- Real-time system integration – The AI can auto-book appointments on your calendar or log data in your CRM during the call, which a human might do after the call or not at all
In short, Synthflow doesn’t just answer calls like a receptionist, it also performs tasks (data entry, scheduling, basic Q&A) automatically.The trade-off: An AI receptionist has certain limits (it handles common queries and processes but isn’t a live person for complex, nuanced issues), so Synthflow is best for front-line call handling and FAQ, with the ability to transfer to humans for anything the AI can’t solve. Many teams use it to capture and qualify leads or handle routine customer inquiries, then involve human staff for high-level or sensitive conversations.
What happens if I exceed the call minutes included in my plan
If you go over your plan’s minute allotment in a month, Synthflow will simply charge overage fees for the additional minutes. The overage rate depends on your plan:
- Pro plan: $0.13 per extra minute
- Growth/Agency plans: $0.12 per minute
- Enterprise plans: As low as ~$0.08 with volume discounts
These per-minute fees are relatively small – for example, an extra 100 minutes on the Pro plan would be $13. Synthflow’s dashboard will show your usage, so you can keep track.
If you find you’re consistently exceeding minutes, it might be more cost-effective to upgrade to the next plan level (since the larger plans have a lower effective per-minute cost). But occasional overages are fine to just pay as you go. There’s no service interruption or anything when you pass your limit; the calls will continue and you’ll simply see additional minutes billed on your invoice.
Essentially, Synthflow’s model is like a cell phone plan with a bucket of minutes and an overage rate – and you can upgrade anytime to get a bigger bucket if needed.
How does Welco.ai compare to Synthflow for small teams?
While both are AI receptionist solutions, they have different philosophies:
Synthflow is fantastic for those who want a highly customizable, build-it-yourself voice AI system – it’s often favored by developers or larger teams that have the resources to design detailed call flows and manage usage. It is for teams who want to build custom workflows from scratch. It offers deep customization but requires technical knowledge, ongoing maintenance, and usage-based billing that can be unpredictable.
Welco.ai is designed for simplicity and easy use. For a small or mid-sized team, Welco can be very attractive because you pay a flat rate (no worrying about minutes) and get a ready-to-go AI receptionist with minimal configuration. Welco focuses on core use cases (answering calls, qualifying leads, booking appointments, FAQs) with an easy UI.This means if you’re a non-technical team or you don’t want to spend time tweaking workflows, Welco might deliver value faster. Also, Welco includes certain conveniences out-of-the-box – e.g., “it will automatically send follow-up texts to callers or do instant call transfers to you when needed, without you scripting that logic. It is built for speed and simplicity. You get a fully functional AI receptionist in minutes with a monthly pricing—no surprise bills, no technical setup required.
