Aircall vs Synthflow: Which AI Voice Agent Fits Your Team?

Aircall and Synthflow both run AI voice agents, but they're sold to different buyers. Synthflow is an enterprise voice AI platform: since mid-2026 it sells only annual contracts, starting at US$30,000 a year, through a sales-led process.

Aircall is an AI-powered platform for customer conversations: the AI Voice Agent runs inside a full business phone system next to your reps, across calls, SMS, and WhatsApp, and you can start free with 50 minutes a month.

Pick Synthflow if you're an enterprise contact centre ready for a large annual commitment. Pick Aircall if you run a sales or support team and want AI and people working from one platform, with pricing that starts at zero.

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What's the difference between Aircall and Synthflow?

The difference comes down to how you buy and who works the calls.

Synthflow builds AI agents that run phone calls at scale, mostly for large contact centres and BPOs. You start with a demo, scope the deployment with their team, and sign an annual contract.

Aircall puts the AI Voice Agent in the same phone system your team already uses. You can sign up, describe what the agent should handle in plain language, and have it answering calls the same day. When a caller needs a person, the call goes to your own reps with the full context attached.

Aircall vs Synthflow at a glance

Here's how the two compare on the points that usually decide it.

What is Synthflow?

Synthflow is a voice AI platform founded in 2023 in Berlin. Its agents answer and place calls, book appointments, qualify leads, and route callers, and it now covers chat and SMS as well as voice. Synthflow runs its own phone network and holds SOC 2, HIPAA, PCI DSS, and GDPR certifications.

In 2026, Synthflow moved upmarket. It retired its self-serve plans and now sells enterprise contracts only, starting at US$30,000 a year and scoped by call volume, concurrency, integrations, and security needs. There's no free trial: every new customer starts with a demo and a sales conversation. Teams that looked at Synthflow before 2026 may remember lower monthly tiers that new buyers can no longer get.

What is Aircall?

Aircall is an AI-powered platform for customer conversations, founded in 2014 in Paris and used by 23,000+ businesses. It combines a business phone system with AI that works alongside your team. The AI Voice Agent handles inbound and outbound calls, and AI Messaging Agents, launched in May 2026, handle SMS and WhatsApp. Calls, texts, and WhatsApp run through one number, one knowledge base, and one workspace.

When a conversation needs a person, it moves to a rep with the full context. Managers see AI and human calls in the same reports, so they can improve both from the same data.

How do Aircall and Synthflow differ?

Six differences matter most when you compare them side by side.

1) Getting started: self-serve vs sales-led

With Aircall, you can sign up, get 100 free trial minutes, and have an AI Voice Agent answering calls the same day. With Synthflow, you book a demo, scope the deployment, and sign an annual contract before your first call goes live. If you want to test AI on real calls this week, Aircall gets you there faster.

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2) An AI agent inside your phone system

Synthflow's agent is the product, and it connects to your phone setup or contact centre platform. Aircall's AI Voice Agent is part of the phone system your team already runs, with the same numbers, call routing, and reporting. There's nothing extra to connect between the AI and your reps.

3) Handoff to your team

AI handles the routine calls, and the hard ones still need a person. Aircall moves callers to the right rep with warm transfer, so your team picks up with the full conversation in front of them. Synthflow supports transfers and escalation paths too, but they lead into whichever phone system or contact centre you connect.

4) Channels beyond voice

Synthflow now covers voice, chat, and SMS. Aircall covers voice, SMS, and WhatsApp on the same business number, with AI agents on each channel and one shared inbox for your team.

5) Integrations and your CRM

Synthflow lists 200+ integrations, including CRMs, calendars, and contact centre platforms. Aircall offers 250+ native integrations with tools like HubSpot, Salesforce, Zendesk, and Shopify. During a call, the AI Voice Agent can look up a record, update a ticket, and log the outcome, with no middle layer.

6) Analytics and coaching

Synthflow reviews every AI conversation with automated QA. Aircall reports on AI and human calls together, adds AI-generated call summaries, and coaches reps in real time with AI Assist Pro. Managers improve the AI and the team from the same data.

How does Aircall pricing compare to Synthflow?

This is where the two differ most. Aircall prices are in GBP and Synthflow prices in USD, as published in October 2026.

Synthflow's US$30,000 floor works out to US$2,500 a month before a single call. Aircall starts free and charges £0.22 per minute after that, with no contract. Current Aircall plans are on the pricing page, and our guide to AI voice agent costs breaks down the rest.

Which one should you choose?

Match the tool to how your team works.

Choose Synthflow if you run a large contact centre or BPO, have the budget for an annual contract from US$30,000, and want a vendor-led rollout with dedicated launch support.

Choose Aircall if you run a sales or support team and want AI and reps on the same conversations, voice plus SMS and WhatsApp on one number, 250+ native integrations, and pricing that starts free. It fits a small business today and scales with you to a larger operation.

Comparing other options too? See how Aircall stacks up against Retell AI, RingCentral, Dialpad, Nextiva, and CloudTalk.

Discover Aircall's AI Voice Agent

Frequently asked questions

What is Synthflow?

Synthflow is a voice AI platform that builds AI agents to answer and place phone calls, mainly for enterprise contact centres. Since 2026, it sells only enterprise contracts, starting at US$30,000 a year.

Does Synthflow have a free trial or self-serve plan?

No. Synthflow retired its self-serve plans in 2026, and new customers start with a demo and a sales conversation. Aircall lets you sign up directly, with 100 trial minutes and 50 free minutes every month.

How much does Synthflow cost?

Synthflow's enterprise contracts start at US$30,000 a year, with final pricing scoped by call volume, concurrency, integrations, and security needs. It doesn't publish a per-minute rate. Aircall's AI Voice Agent costs £0.22 per minute after 50 free minutes a month, with no contract.

What are the best Synthflow alternatives?

It depends on what you need. If you want AI voice agents inside a full business phone system, with handoff to your own reps and pricing that starts free, Aircall is a strong option. Developer-first platforms like Retell AI suit teams that want to build custom agents in code.

Is Aircall or Synthflow better for a sales or support team?

Aircall, for most teams. AI agents, human handoff, and CRM sync run on one platform, and you can start without a sales process or annual contract. Synthflow fits large contact centres that want a vendor-led enterprise deployment.

Does Aircall have an AI voice agent?

Yes. Aircall's AI Voice Agent handles inbound and outbound calls in 38 languages, and AI Messaging Agents handle SMS and WhatsApp, all in the same platform your team uses for live calls.