Synthflow AI Review: How to Stop Missing Costly Leads

Have you ever missed a lead because your team was too busy to pick up the phone? Missed calls cost businesses millions every year, yet 45 million calls now run through Synthflow AI without breaking a sweat.

When I tried Synthflow myself, I wanted to see if it could take the pain out of handling calls, booking appointments, and following up without having to write a single line of code.

In this Synthflow AI review, I’ll discuss the pros and cons, what it is, who it’s best for, and its key features. Then, I’ll show you how I used Synthflow AI to create a custom AI assistant and implement it into my workflow.

I’ll finish the article by comparing Synthflow AI with my top three alternatives (Synthesys AI Calls, PolyAI, and Vapi). By the end, you’ll know if Synthflow AI is right for you!

Verdict

Overall, Synthflow AI makes it easy to launch lifelike, 24/7 voice agents fast with no code and easy integrations. Just be ready to spend more time and money on advanced workflows and heavy use.

What is Synthflow AI?

Synthflow AI is an AI platform that automates and manages phone calls using AI voice agents. Businesses can create, customize, and implement AI voice assistants for inbound and outbound calls. These AI Voice Assistants handle tasks like answering questions, booking appointments, routing calls, detecting voicemails, and sending SMS follow-ups (no coding skills required!)

Founded in 2023 and based in Berlin, Germany, Synthflow AI has quickly gained traction. They serve over 1,000 customers and handle more than 45 million calls as of mid-2025.

AI Voice OS

Synthflow uses what they call a “Complete AI Voice OS.” Think of it as the operating system for all your phone conversations: everything from call routing to resolution happens in one unified platform.

What impressed me was how they handle the entire voice conversation lifecycle. With Synthflow, you get telephony via SIP trunking, custom workflows, and multilingual support all baked into one system.

The platform handles over 45 million customer calls, which means it can handle much smaller volumes. When you’re doing customer service, reliability isn’t negotiable.

Technical Infrastructure

Synthflow uses enterprise-grade infrastructure with 99.9% uptime guarantees, SOC2, HIPAA, and GDPR compliance. The data stays protected with end-to-end encryption.

Synthflow also offers SIP trunking, so you don’t have to replace your existing phone system. The API design means everything can be customized if needed, and the no-code tools handle most use cases.

The multilingual support covers 10+ languages with natural-sounding voices. It’s sophisticated enough to handle some regional accents, including American, British, and Australian.

Integrations

Instead of adding complexity to tech stacks, Synthflow is the central hub that connects everything. The platform talks to Salesforce, GoHighLevel, Stripe, Google Calendar, and basically every major business tool you’re probably already using.

Synthflow can really streamline your operations. Rather than data living on multiple systems, voice agents can access everything in real-time, book appointments, send confirmations, and update CRMs automatically.

The webhook system lets you trigger actions in external systems based on conversation outcomes. For example, when someone books an appointment through a voice agent, it automatically creates calendar events, sends confirmation emails, and updates the patient record.

The bottom line is this: Synthflow isn’t just another AI tool. It makes your entire communication system smarter and more efficient.

Whether you’re handling customer support, sales calls, or appointment scheduling, Synthflow eliminates the frustrating gaps between different tools and creates one seamless experience for both your team and your customers.

Who is Synthflow AI Best For?

Here are the types of people who will get the most out of Synthflow AI:

• Enterprises can use Synthflow AI to scale secure, compliant voice automation for healthcare, banking, and finance.
• SMEs (Small and Medium-Sized Enterprises) can use Synthflow AI to quickly set up advanced AI voice agents with its no-code platform.
• Customer support and sales teams can use Synthflow AI to automate calls, handle high volumes, and free up staff for complex tasks.
• Organizations that need integration can use Synthflow AI to connect with 200+ tools like CRMs, calendars, and phone systems.
• Companies replacing old IVR or BPO systems can use Synthflow AI to modernize with natural-sounding AI voice agents.

Synthflow AI Key Features

Here are Synthflow AI’s key features:

1. No-Code Interface: Build and launch AI voice agents without coding.
2. Customizable AI Voice Assistants: Tailor voice agents to fit your brand and handle tasks like customer support, marketing, or content delivery.
3. Human-Like Voices: Multiple voice options to make calls more engaging.
4. Multilingual & Accent Support: Speak in 10+ languages and use English accents (American, British, or Australian) to reach a diverse global audience.
5. Real-Time Voice Interactions: Have smooth, low-latency conversations (under 500ms) for live customer support, sales, and service.
6. Stage Recognition: Detects conversation stages and adjusts replies to keep context clear in sales or support workflows.
7. Integration: Connects easily with CRMs, calendars, Zapier, HubSpot, and other tools to automate tasks and trigger actions.
8. Appointment Scheduling: Automates booking, rescheduling, calendar management, and sends reminders to reduce no-shows and optimize staff time.
9. Sales & Lead Generation: Initiates outbound calls, qualifies prospects, and routes high-intent leads to your team to boost sales.
10. Customer Support Automation: Handles common questions, solves basic issues, and offers 24/7 help so human agents can focus more on complex cases.
11. Visual Builder: Drag-and-drop tool to create conversation flows, add questions, replies, and actions.
12. Monitoring & Analytics: Track calls, agent results, and performance to keep improving.
13. Enterprise-Ready: Designed for scalability, security, and compliance.

How to Use Synthflow AI

Here’s how I used Synthflow AI to create and implement a custom AI assistant:

1. Start the Free Trial
2. Choose a Template
3. Create an AI Assistant
4. View the Dashboard
5. Configure the Settings
6. Create a Prompt
7. Create Custom Actions
8. Add Deployment Details
9. Access Your Calls
10. Add a Knowledge Base
11. Create API Triggers
12. Automate Workflows
13. Choose a Workflow Preset
14. Edit Your Workflow
15. Import Contacts & Connect Apps

Step 1: Start the Free Trial

I started by going to synthflow.ai and selecting “Free Trial” on the top right.

Step 2: Choose a Template

After creating an account, I was taken to the Agents page.

There were three ways I could create agents:

1. Start from scratch (build an AI agent from the ground up)
2. Quick agent setup (use presets to streamline agent setup)
3. Browse the templates (begin building an AI agent by choosing a template)

While you can build an AI agent from scratch, the fastest and easiest way to create an AI agent with Synthflow is with a template. I selected “Browse our templates.”

There were two types of AI agents I could choose from:

• Inbound (manage incoming calls via phone, Zapier, REST API, or HighLevel)
• Outbound (automate calls within workflows using Zapier, REST API, or HighLevel)

I went with “Inbound” and selected Customer Support for a car dealership. Synthflow AI offers templates in a wide range of industries, including real estate, healthcare, recruitment, and more.

If you can’t find a template that exactly fits what you’re looking for, choose the one that comes closest and tweak it. Otherwise, create a new agent from scratch.

Step 3: Create an AI Assistant

After selecting my template, Synthflow AI gave me an overview of the AI assistant. I selected “Create Assistant.”

Next, I selected my agent from the list.

Step 4: View the Dashboard

Selecting the agent took me to the agent’s dashboard. This was where I could view recorded calls, actions, and analysis.

Step 5: Configure the Settings

Below “Dashboard” is “Configure.” This is where you can configure general settings about your AI agent:

• Name
• Image
• Voice engine
• AI model
• Timezone
• Knowledge base
• Custom vocabulary
• Filter words

Step 6: Create a Prompt

The “Prompt” tab allowed me to customize what my AI agent says. I had the freedom to edit the greeting message and the prompt, which included background information.

Synthflow AI had already provided the structure of the prompt, making it easy to personalize it for my business/dealership.

Step 7: Create Custom Actions

“Actions” allowed me to add custom actions that run before, during, and after the call.

Step 8: Add Deployment Details

“Deployment” was where I could connect the phone number to be used, add the webhook to receive notifications from the agent, and configure integrations to automate the process.

Step 9: Access Your Calls

“Calls” was where I could access my calls and contacts.

Besides the settings you can adjust within the AI agent, there are also some other tools you should be aware of.

Step 10: Add a Knowledge Base

The knowledge base is where you can upload your website or text for your AI assistant to refer to.

Selecting “Get Started” in the knowledge base opened a new window where I could add a name and describe when the AI agent should search it.

Step 11: Create API Triggers

“Actions” allowed me to create API triggers to integrate my assistant into a database or create/update records.

Here are the actions I could implement:

• Real-time booking
• Call transfer
• Information extractor
• Send SMS
• Custom action
• IVR

Step 12: Automate Workflows

“Workflows” (also known as the “Flow Designer) was where I could automate “flows” to tell the AI agent what to do. For example, I could automate call flows, including actions like booking, transfers, and updating records.

I could either create a workflow from scratch or select one of the presets to streamline the setup. I wanted to explore the presets, so I selected “Use Presets.”

Step 13: Choose a Workflow Preset

Synthflow presented multiple presets to automate outbound calls, process inbound calls, gather data, and more. I selected the first preset to automate outbound calls.

Step 14: Edit Your Workflow

After naming my workflow, I could view the entire thing and make edits to the existing steps by clicking on them and making adjustments in the right panel.

Hitting the “+” button revealed more actions I could add to my workflow, like AI agents, apps, and tables.

Step 15: Import Contacts & Connect Apps

Last but not least were Contacts, Phone Numbers, and Integrations. I could create or import contacts and connect third-party apps to be used in workflows.

Overall, Synthflow AI made setting up an AI agent quick and easy. The templates, prompt tools, and workflow presets helped me get started fast with full customization.

Top 3 Synthflow AI Alternatives

Here are the best Synthflow AI alternatives I’d recommend.

Synthesys AI Calls

The first Synthflow AI alternative I’d recommend is Synthesys AI Calls. It’s a tool that helps businesses automate phone conversations with lifelike, multilingual AI agents. It has a no-code interface and deep integration capabilities.

Both platforms give you the ability to create and launch AI voice agents without coding. They’re both excellent choices for automating customer support, sales, and appointment scheduling.

However, Synthesys AI Calls stands out with its voice cloning feature for more personalization. It also comes with built-in analytics and reporting to help track performance and optimize call flows.

Meanwhile, Synthflow AI is known for its seamless integrations (supporting 200+ tools), automatic appointment scheduling, and flexible call routing.

For fast, no-code setup with strong integrations, choose Synthflow AI. For voice cloning features for more personalization, try Synthesys AI Calls.

PolyAI

The next Synthflow AI alternative I’d recommend is PolyAI. PolyAI is an AI voice platform for call centers to automate complex customer conversations. It specializes in handling high-volume inbound calls, supports multilingual interactions, and is known for its exceptionally lifelike AI voices.

On the one hand, PolyAI stands out with its excellent voice quality and ability to handle nuanced conversations (including interruptions and topic changes). This makes PolyAI a strong fit for enterprises that prioritize customer experience.

PolyAI also comes with real-time analytics and can be custom-deployed in as little as six weeks. However, it lacks a no-code interface, so making changes or updates often needs technical skills or developer help. This can slow down quick iterations and may prevent building and testing new workflows.

Meanwhile, Synthflow AI is designed for speed and flexibility. With Synthflow AI, you’ll get a no-code visual builder and an extensive library of integrations (200+). Teams can easily launch, update, and manage AI agents without coding or external support.

Synthflow’s transparent, usage-based pricing makes it accessible to both startups and enterprises. Meanwhile, PolyAI’s custom enterprise contracts are more expensive.

For fast setup and simple workflows, choose Synthflow AI. For the most natural voices and a more custom solution, choose PolyAI.

Vapi

The final Synthflow AI alternative I’d recommend is Vapi. Vapi offers voice AI agents, emphasizing real-time interaction and low-latency conversations. It’s a good option for scalable voice tools with 40+ integrations.

Both platforms enable you to launch AI voice agents without code. However, Vapi stands out with its excellent conversation quality, supporting interruption detection, orchestration models for more natural interactions, and scalability. Vapi also offers multilingual support in over 100 languages, flexible usage-based pricing, and integration with APIs.

Meanwhile, Synthflow AI is great for non-technical users who want a no-code platform for quick deployment. It comes with features like batch outbound campaigns, customizable voice agents, and seamless integration with 200+ business tools. Synthflow’s latency is impressively low (under 500ms), and its drag-and-drop builder simplifies workflow automation for customer service, sales, and scheduling.

For excellent conversation quality and flexible development tools, choose Vapi. For quick, easy, no-code setup with strong workflow integration, choose Synthflow AI!

Synthflow AI Review: The Right Tool For You?

Overall, Synthflow AI made setting up a smart, reliable AI voice agent fast and stress-free. The templates and deep integrations saved me hours I’d usually spend stitching tools together, and the human-like voices made everything feel professional.

If you’re looking for a simple way to automate calls, book appointments, and connect tools without coding headaches, Synthflow AI is a solid choice. Otherwise, consider these alternatives:

• Synthesys AI Calls is best for voice cloning and detailed call analytics.
• PolyAI is best for big companies that want realistic voices and full management.
• Vapi is best for developers who want great call quality, flexible APIs, and global languages.

Thanks for reading my Synthflow AI review! I hope you found it helpful.

Synthflow AI offers a 14-day free trial on any of its plans. Try it for yourself and see how you like it!

Frequently Asked Questions

What does Synthflow AI do?

Synthflow AI lets businesses automate calls and customer interactions with human-like AI agents. It has a visual builder, multilingual support, and connects easily to CRMs and calendars to keep communication smooth.

Who is the CEO of Synthflow AI?

The CEO of Synthflow AI is Hakob Astabatsyan. He is also a co-founder of the company, which is headquartered in Berlin and was founded in 2023.

What is the best AI outbound calling bot?

Synthflow AI is the best AI outbound calling bot for large-scale campaigns and high-volume calling with easy setup.