Alternative
Call0 as an alternative to Synthflow
On its own website, Synthflow describes itself as an enterprise platform for automated phone calls. Call0 is aimed at small and medium-sized businesses.
On this page
Our recommendation
Our recommendation · as of 27 October 2026
For most small and medium-sized businesses we recommend Call0 over Synthflow.
Synthflow has its strengths, which we list further down with sources. For most small and medium-sized businesses we recommend Call0, for these reasons:
- Live the same day
- Enter your website, and Call0 builds the assistant from it. 15 test minutes in the browser, without a credit card or sales call.
- Several lines from the first plan
- Launch includes 3 concurrent calls, 700 minutes and 1 phone number. Nobody hears a busy tone when two customers call at once.
- A person takes over when it matters
- Handover to your team with a queue, hold music, opening hours and a callback list. The caller is never left hanging.
- Phone, WhatsApp, email and chat in one account
- One knowledge base for every channel. You maintain it once, and every assistant answers the same way.
- Over 500 integrations
- Appointments land in your calendar, requests in your CRM or ticketing system, without manual copying.
- Set up in conversation
- Agent0 sets up the assistant with you and changes it when you ask. No prompt writing, no flow builder.
The facts side by side
What both providers publish themselves, with source and date of the check.
| Feature | Call0 | Synthflow |
|---|---|---|
| Focus according to the provider | AI assistant for phone, WhatsApp, email and website chat for small and medium-sized businesses; handover to staff with a queue; the agent is created from the company’s own websiteSource: call0.ai | Voice AI platform that companies use to automate phone callsSource: synthflow.ai |
| Entry price and what it includes | Launch: €110 per month or €1,188 per year; 700 minutes, 3 concurrent calls; netSource: call0.ai | Enterprise contracts from $30,000 per year; no other plans are stated on the pricing pageSource: synthflow.ai |
| Free trial | Yes, 15 test minutes without a credit card; no phone number in the Free planSource: call0.ai | According to the homepage, an agent can be created free of charge; usage-based billing from go-liveSource: synthflow.ai |
| German | Website and product in German; 13 agent languagesSource: call0.ai | Pages checked are in English; the number of languages is not stated thereSource: synthflow.ai |
| How to start | Sign up online; Enterprise on requestSource: call0.ai | Contact salesSource: synthflow.ai |
| Phone number | 1 number included in the Launch plan; each additional one €15 per month; forwarding your own number requires a paid planSource: call0.ai | The provider’s own telephony, SIP trunking or approved enterprise telephonySource: synthflow.ai |
| Integrations named | Over 500 in the directory, including calendars, CRM and ticketing systems; WhatsApp availableSource: call0.ai | HubSpot, Salesforce, Zapier, Cal.com, GoHighLevel, GenesysSource: synthflow.ai |
| Provider’s registered seat | Call0 Inc., New York, USASource: call0.ai | AgentFlow AI GmbH, Berlin, GermanySource: docs.synthflow.ai |
Switching to Call0 pays off if …
- you want to start online today without a sales call
- the assistant should be created from your website
- 3 concurrent calls should be included from the entry plan (Launch) onwards
- calls should be handed over to your team when a person is needed, with a queue, hold music and opening hours
- besides the phone, you also want to answer WhatsApp, email and the website chat with the same knowledge
- you would rather tell Agent0 what to change than build flows yourself
What Call0 does besides the phone
One account, one knowledge base, every channel.
- Phone assistant
Answers calls around the clock, books appointments, records requests and makes outbound calls. Speaks 13 languages.
Phone assistant → - Handover to your team
When a person is needed, the phones of your team ring: queue with hold music, ringing in turn, hold and transfer, opening hours and fallback rules.
- WhatsApp assistant
Replies to customer messages on WhatsApp with the same knowledge as on the phone. You choose between assist, approval and autopilot.
WhatsApp assistant → - Email assistant
Reads your inbox and prepares replies. Sensitive topics always go to a person; nothing is deleted or archived.
Email assistant → - Website chatbotComing soon
Answers visitors on your website from the same knowledge and hands over requests to your team.
Website chatbot → - Agent0 and integrations
Agent0 sets up and adjusts the assistant with you in plain language. Over 500 integrations connect calendars, CRM and ticketing systems.
Integrations →
What Synthflow highlights itself
Fair is fair: this is what the provider writes about itself, each with a source.
- Synthflow sells enterprise contracts and states an annual amount for them. Source: synthflow.ai
- The website names connections to HubSpot, Salesforce and contact center platforms such as Genesys. Source: synthflow.ai
- The pricing page names the provider’s own telephony, SIP trunking or approved enterprise telephony. Source: synthflow.ai
How to switch smoothly
Concurrent calls
If several callers should get through at the same time, a plan with one line does not help, however low its price.Term and setup fee
For a pilot, a plan that can be cancelled monthly is usually the simpler choice.Keeping your number
Forwarding when the line is busy or outside opening hours is usually the easiest start; porting is rarely needed.Data
Ask where the language model and transcripts are processed, how long they are stored and whether there is a data processing agreement.
More alternatives to Synthflow
According to each provider’s own focus, with sources in the provider comparison.
- Parloa · Enterprise customer service with a contact center platform
- Cognigy · Large companies with their own contact center
- fonio · Businesses in German-speaking countries looking for fixed minute packages and a provider in the EU
- Placetel AI · Businesses that already use a phone system and want to add the assistant
- voiceOne · Small businesses, practices and law firms that want to set up online themselves
- Audelia · Businesses that want to combine AI with a human phone team
Frequently asked questions
Does Synthflow have a plan for small businesses?
The pricing page states enterprise contracts only. The homepage says that you can create an agent free of charge. Both statements are in the table with their source.
Who is Call0 intended for?
For small and medium-sized businesses that want to start without a sales call. The plans are published on the pricing page.
As of 27 October 2026. The ranking follows the criteria named on the page. Information about other providers comes from their linked pages and was checked on the date stated; the provider’s own page is authoritative. Brand names belong to their owners; no partnership is claimed. If an item is no longer correct, write to support@call0.ai.