Comparison

The best AI phone assistants 2026 compared

Our top 10 for small and medium-sized businesses and all 22 providers with prices, trials, languages and integrations side by side. Every item with source and date of the check.

  • As of 27 October 2026
  • 22 providers
  • Sources linked
On this page
  1. Our recommendation
  2. The top 10 AI phone assistants 2026
  3. All providers side by side
  4. What Call0 does besides the phone
  5. How we rated
  6. The other providers at a glance
  7. How to test two providers
  8. Frequently asked questions

Which AI phone assistant is the best?

Our recommendation · as of 27 October 2026

For most small and medium-sized businesses we recommend Call0.

The Launch entry plan already includes 3 concurrent calls and 700 minutes, and the same account covers WhatsApp, email and the website chat with one shared knowledge base.

Our top 5: 1. Call0, 2. fonio, 3. VITAS, 4. Placetel AI, 5. sipgate sona. Teams that build voice agents themselves will find developer platforms in ElevenLabs Agents, Retell AI and Vapi; Cognigy, Parloa and Synthflow address the contact centers of large companies, and Doctolib KI-Telefonassistent, HalloPetra and Ordicall specialise in single industries.

Everything about the 21 other providers comes from their own pages, with source and date.

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.
Try it for freeCall0 and fonio in detail

The top 10 AI phone assistants 2026

Our ranking for small and medium-sized businesses in the German-speaking market, rated on channels, handover to people, concurrent calls, start and price.

  1. 01

    Call0Website

    Everything in one account: phone, WhatsApp, email and website chat in one account, with the same knowledge. Launch already includes 3 concurrent calls and 700 minutes. When a person is needed, Call0 hands over to your team, with a queue, hold music and opening hours. It is built from your website and changed in conversation with Agent0.

    Best for
    Businesses that want one assistant for phone, WhatsApp, email and chat, with handover to their team
    Entry
    Launch: €110 per month or €1,188 per year; 700 minutes, 3 concurrent calls; netSource: call0.ai
  2. 02

    fonioWebsite

    Established phone assistant from Austria with fixed minute packages and many industry examples. The Solo plan includes many minutes but only one concurrent call.

    Best for
    Businesses in German-speaking countries looking for fixed minute packages and a provider in the EU
    Entry
    Solo: €119 per month with monthly billing, €99 per month with annual billing; 1,000 minutes, 1 concurrent call; netSource: fonio.ai
  3. 03

    VITASWebsite

    Phone assistant with guidance at the start and a 30-day trial. Billing is per conversation instead of per minute.

    Best for
    Companies in any industry that want to test for 30 days and get advice on the setup
    Entry
    FLEX: €49 per month with no included volume, then €0.28 per conversation; netSource: telefonassistent.de
  4. 04

    Placetel AIWebsite

    The obvious choice for businesses that already use Placetel as their phone system: the assistant is simply added there.

    Best for
    Businesses that already use a phone system and want to add the assistant
    Entry
    Grow: €69 per month with a 24-month term, €79 per month with a shorter term; 750 minutes includedSource: placetel.de
  5. 05

    sipgate sonaWebsite

    Start with a permanently free plan, a good fit for very small businesses with few calls.

    Best for
    Small businesses that want to begin with a permanently free plan
    Entry
    Free: €0 per month with 500 minutes and 1 concurrent call; Starter: €69.95 per month with 1,000 minutes; netSource: sipgate.de
  6. 06

    FamulorWebsite

    Usage-based without a base fee and strong on automation. A good fit for agencies that build for clients.

    Best for
    Companies and agencies that want to start usage-based without a base fee
    Entry
    Plus: €27 per month with annual billing, with 100 minutes; also Prepaid with no base fee at €0.15 per minuteSource: famulor.io
  7. 07

    HalloPetraWebsite

    Clearly focused on the trades, with functions that fit the office routine of a trade business.

    Best for
    Trade businesses that want to hand over calls by call forwarding
    Entry
    Einzelkämpfer (solo operator): €99 per month for 1 employeeSource: hallopetra.de
  8. 08

    voiceOneWebsite

    For practices, law firms and service providers in the German-speaking market; prices are not published.

    Best for
    Small businesses, practices and law firms that want to set up online themselves
    Entry
    not stated publicly; the plans Basic, Premium and Professional are namedSource: voice-one.ai
  9. 09

    AudeliaWebsite

    Combines AI with a human phone team of the provider, for businesses that want both from one source.

    Best for
    Businesses that want to combine AI with a human phone team
    Entry
    Essential: €49 per month with 150 AI minutes; netSource: audelia.com
  10. 10

    Doctolib KI-TelefonassistentWebsite

    Doctolib’s phone assistant, a sensible choice for medical practices that already work with Doctolib.

    Best for
    Medical practices that want to use a phone assistant from Doctolib
    Entry
    not stated publiclySource: info.doctolib.de

All providers side by side

Every cell reproduces what the provider writes on the linked page. “Not stated publicly” means: the page that was checked says nothing about it. Call0 is at the top as our recommendation, then alphabetical.

As of 27 October 2026. The source of every item is the linked page of the provider. Prices in the currency stated there.
ProviderFocus according to the providerEntry price and what it includesFree trialGermanHow to startPhone numberIntegrations namedProvider’s registered seat
Call0As of 27 October 2026Our recommendation
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
Launch: €110 per month or €1,188 per year; 700 minutes, 3 concurrent calls; netSource: call0.ai
Yes, 15 test minutes without a credit card; no phone number in the Free planSource: call0.ai
Website and product in German; 13 agent languagesSource: call0.ai
Sign up online; Enterprise on requestSource: call0.ai
1 number included in the Launch plan; each additional one €15 per month; forwarding your own number requires a paid planSource: call0.ai
Over 500 in the directory, including calendars, CRM and ticketing systems; WhatsApp availableSource: call0.ai
Call0 Inc., New York, USASource: call0.ai
AudeliaAs of 16 October 2026
“Der hybride KI-Telefonassistent” (the hybrid AI phone assistant): AI and a human team; trades, car dealerships, property management and medical practices are named, among othersSource: audelia.com
Essential: €49 per month with 150 AI minutes; netSource: audelia.com
Yes, 14 days without a credit card; the trial ends automaticallySource: audelia.com
Website in German; multilingual support is named, number of languages not stated publiclySource: audelia.com
Free online trial, book a demo or request a callbackSource: audelia.com
not stated publiclySource: audelia.com
Salesforce, Microsoft 365, Google Calendar, Microsoft BookingsSource: audelia.com
Audelia GmbH, Berlin, GermanySource: audelia.com
CognigyAs of 16 October 2026
“KI-Agenten für den Enterprise-Kundenservice” (AI agents for enterprise customer service); according to the website, Cognigy is part of NiCESource: cognigy.com
not stated publiclySource: cognigy.com
not stated publiclySource: cognigy.com
Website in German and English; over 100 languages for voice AI according to the providerSource: cognigy.com
Request a demoSource: cognigy.com
not stated publicly; connection to existing telephony via the Voice GatewaySource: cognigy.com
Avaya, Amazon Connect, Genesys, NiCE CXone, Microsoft, 8x8Source: cognigy.com
Cognigy GmbH, Düsseldorf, GermanySource: cognigy.com
Doctolib KI-TelefonassistentAs of 6 October 2026
AI phone assistant for calls in medical practicesSource: info.doctolib.de
not stated publiclySource: info.doctolib.de
not stated publiclySource: info.doctolib.de
Website in GermanSource: info.doctolib.de
Consultation call via a contact formSource: info.doctolib.de
not stated publiclySource: info.doctolib.de
not stated publiclySource: info.doctolib.de
Doctolib GmbH, Berlin, GermanySource: doctolib.de
ElevenLabs AgentsAs of 6 October 2026
Platform for conversational AI agents (voice and chat)Source: elevenlabs.io
Free: $0 with 15 minutes; Starter: $6 per month with 75 minutes; according to the pricing page, LLM costs are charged in additionSource: elevenlabs.io
Yes, Free plan with 15 minutesSource: elevenlabs.io
Website in German; over 90 languages according to the providerSource: elevenlabs.io
Sign up online; Enterprise via salesSource: elevenlabs.io
Connection via Twilio or SIP; the telephony provider’s costs are charged separatelySource: elevenlabs.io
Twilio, Zapier, Cal.com, Zendesk, HubSpot, StripeSource: elevenlabs.io
Eleven Labs Inc., New York, USASource: elevenlabs.io
elunos.aiAs of 16 October 2026
“KI-Telefonassistenten für jedes Unternehmen” (AI phone assistants for every business); templates for over 15 industriesSource: elunos.ai
Price table: Starter €89 per month billed over 2 years, with 1,000 minutes; the FAQ on the same page states €99 with annual and €119 with monthly paymentSource: elunos.ai
“Einen kostenlosen Tarif gibt es nicht” (there is no free plan); plus “30 Tage Geld-zurück-Garantie” (money-back guarantee)Source: elunos.ai
Website in German and English; according to the provider, the agent speaks German and English, more languages are to followSource: elunos.ai
Sign up online or book a demoSource: elunos.ai
The existing number stays with the telephone provider; connected via SIP trunk or call forwardingSource: elunos.ai
HubSpot, Salesforce, Google Calendar, Microsoft 365, Calendly, DoctolibSource: elunos.ai
elunos.ai Labs UG, Frankfurt am Main, GermanySource: elunos.ai
FamulorAs of 16 October 2026
“Plattform für KI-Telefonassistenten aus Deutschland” (platform for AI phone assistants from Germany); for companies and agenciesSource: famulor.io
Plus: €27 per month with annual billing, with 100 minutes; also Prepaid with no base fee at €0.15 per minuteSource: famulor.io
Yes, Prepaid at €0 to start with 800 credits included, without a credit cardSource: famulor.io
Website in German; according to the provider, the voicebot speaks German, English, Spanish, French and DutchSource: famulor.io
Sign up online without a credit card or book a demoSource: famulor.io
No number included in Prepaid, Plus and Pro; each additional number €2 per month; call forwarding and SIP trunk possibleSource: famulor.io
Zendesk, Freshdesk, Intercom, ServiceNow, Slack, Microsoft TeamsSource: famulor.io
BEK Service GmbH, Kempten, GermanySource: famulor.io
fonioAs of 6 October 2026
AI phone assistant in German; the homepage names medical practices, lawyers, car repair shops, hotels and tradespeople, among othersSource: fonio.ai
Solo: €119 per month with monthly billing, €99 per month with annual billing; 1,000 minutes, 1 concurrent call; netSource: fonio.ai
Homepage: “Kostenlose personalisierte KI” (free personalised AI), can be created in 30 seconds; the pricing page does not mention a free trial period for the plansSource: fonio.ai
Website and product in German; over 60 languages according to the pricing pageSource: fonio.ai
Start online (Solo and Team plans)Source: fonio.ai
1 number included in the Solo plan; each additional one €9 per monthSource: fonio.ai
Slack, Salesforce, HubSpot, Calendly, Trello, NotionSource: fonio.ai
fonio GmbH, Vienna, AustriaSource: fonio.ai
HalloPetraAs of 6 October 2026
AI phone assistant and office assistant (“Bürokraft”) for the skilled tradesSource: hallopetra.de
Einzelkämpfer (solo operator): €99 per month for 1 employeeSource: hallopetra.de
Yes, free trial without a credit cardSource: hallopetra.de
Website in GermanSource: hallopetra.de
Sign up onlineSource: hallopetra.de
Connected to the existing phone system by call forwardingSource: hallopetra.de
Trade software (e.g. TAIFUN), Google Calendar, Outlook, HubSpot, ZapierSource: hallopetra.de
HalloPetra GmbH, Berlin, GermanySource: hallopetra.de
IONOS KI TelefonassistentAs of 16 October 2026
“Für Unternehmen, die keinen Kundenanruf mehr verpassen möchten” (for businesses that no longer want to miss a customer call); automated phone serviceSource: ionos.de
Flex: €39 per month, cancellable monthly; 30 calls included, then €0.49 per call; billing is per call, not per minuteSource: ionos.de
Yes, according to the product page “1 Monat gratis testen” (free trial for a month)Source: ionos.de
Website in German; number of languages not stated publiclySource: ionos.de
Book online; setup uses the website address and a dashboardSource: ionos.de
Own new phone number included; alternatively call forwarding from the existing numberSource: ionos.de
Google Calendar, Outlook, Calendly, Cal.com, HubSpot, SalesforceSource: ionos.de
IONOS SE, Montabaur, GermanySource: ionos.de
livestepAs of 16 October 2026
Brand intelligence platform; AI telephony is an add-on module that answers calls, qualifies requests and books appointments or forwards callsSource: livestep.ai
Platform Starter €89 per month plus AI telephony €49 per month per agent; billed in credits, 5 per minute; netSource: livestep.ai
Yes, 7 days without a credit card for the platform; whether AI telephony is included is not stated thereSource: livestep.ai
Website in German; languages of the phone agent not stated publiclySource: livestep.ai
Book a demo or sign up onlineSource: livestep.ai
“Neue Nummer oder Weiterleitung aus deiner bestehenden” (new number or forwarding from your existing one)Source: livestep.ai
SharePoint and Confluence as knowledge sourcesSource: livestep.ai
livestep ApS, Fjerritslev, DenmarkSource: livestep.ai
OrdicallAs of 16 October 2026
“KI-Telefonassistent für Arztpraxen” (AI phone assistant for medical practices): single and group practices, MVZ and clinicsSource: ordicall.ai
From €89 per month; included minutes not statedSource: ordicall.ai
Yes, “Jetzt 30 Tage gratis testen” (free trial); also “30 Tage Geld-zurück-Garantie” (money-back guarantee)Source: ordicall.ai
Website in German; over 60 languages according to the providerSource: ordicall.ai
Book a demo or request a callback; guided setupSource: ordicall.ai
“Eigene Ordicall-Rufnummer” (own Ordicall phone number) included; price of additional numbers not stated publiclySource: ordicall.ai
Offisy, Care01, Medstar, Quickticket, E-termin, easyOrdiSource: ordicall.ai
Ordicall FlexCo, Marchtrenk, AustriaSource: ordicall.ai
ParloaAs of 6 October 2026
AI agents for the customer service of enterprise companiesSource: parloa.com
not stated publicly; according to the pricing page, billing is usage-based per minuteSource: parloa.com
not stated publiclySource: parloa.com
Website in German and EnglishSource: parloa.com
Book a demo via salesSource: parloa.com
not stated publiclySource: parloa.com
Genesys, Amazon Connect, Cisco, Avaya, Five9, Salesforce Service CloudSource: parloa.com
Parloa GmbH, Berlin, GermanySource: parloa.com
Placetel AIAs of 16 October 2026
AI phone assistant; according to the provider it works with any common communication solutionSource: placetel.de
Grow: €69 per month with a 24-month term, €79 per month with a shorter term; 750 minutes includedSource: placetel.de
Yes, 10 days with 50 free minutesSource: placetel.de
Website in GermanSource: placetel.de
Start the trial from the pricing pageSource: placetel.de
Phone number package for €9 per month per AI phone assistantSource: placetel.de
Microsoft Teams, Salesforce, Google Calendar, Zoho, HubSpotSource: placetel.de
Gamma Placetel GmbH, Cologne, GermanySource: placetel.de
Retell AIAs of 6 October 2026
Platform for building, deploying and managing AI voice agents for phone callsSource: retellai.com
Usage-based with no base fee: $0.07 to $0.31 per minute, depending on model and voiceSource: retellai.com
Yes, $10 in starting creditSource: retellai.com
Website in English; multilingual agents according to the provider, the number of languages is not stated thereSource: retellai.com
Sign up online; Enterprise with custom pricingSource: retellai.com
$2 per month per number; your own numbers can be connected at no extra chargeSource: retellai.com
Twilio, Vonage, Make, n8n, HubSpot, GoHighLevelSource: retellai.com
Retell AI Inc., Redwood City, California, USASource: retellai.com
RufLabAs of 16 October 2026
“KI-Telefonassistent für deutsche Unternehmen” (AI phone assistant for German businesses); trades, medical practices, restaurants, property management and tax advisers are named, among othersSource: ruflab.com
Solo: from €69 per month with 500 minutes and 1 phone number; netSource: ruflab.com
Yes, “14 Tage kostenlos testen” (free trial)Source: ruflab.com
Website in German; over 30 languages according to the providerSource: ruflab.com
Sign up online: enter the website address, the assistant is created from it; alternatively book a demoSource: ruflab.com
Phone number included in the plan; alternatively forwarding of the existing numberSource: ruflab.com
HubSpot, Pipedrive, SalesforceSource: ruflab.com
All4Flow Digital, Remscheid, GermanySource: ruflab.com
sipgate sonaAs of 6 October 2026
AI phone assistant that answers calls, books appointments and provides informationSource: sipgate.de
Free: €0 per month with 500 minutes and 1 concurrent call; Starter: €69.95 per month with 1,000 minutes; netSource: sipgate.de
Yes, permanently free plan with 500 minutes per monthSource: sipgate.de
Website in GermanSource: sipgate.de
Start onlineSource: sipgate.de
One phone number is includedSource: sipgate.de
HubSpot, Zoho, Pipedrive, Shopify, Zendesk; calendar via cal.com; plus MCP, APIs and webhooksSource: sipgate.de
sipgate GmbH, Düsseldorf, GermanySource: sipgate.de
SynthflowAs of 6 October 2026
Voice AI platform that companies use to automate phone callsSource: synthflow.ai
Enterprise contracts from $30,000 per year; no other plans are stated on the pricing pageSource: synthflow.ai
According to the homepage, an agent can be created free of charge; usage-based billing from go-liveSource: synthflow.ai
Pages checked are in English; the number of languages is not stated thereSource: synthflow.ai
Contact salesSource: synthflow.ai
The provider’s own telephony, SIP trunking or approved enterprise telephonySource: synthflow.ai
HubSpot, Salesforce, Zapier, Cal.com, GoHighLevel, GenesysSource: synthflow.ai
AgentFlow AI GmbH, Berlin, GermanySource: docs.synthflow.ai
VapiAs of 6 October 2026
Voice AI platform with usage-based billing; according to the pricing page, model costs are passed on at costSource: vapi.ai
$0 to start; $0.05 per minute for Vapi hosting, model costs are addedSource: vapi.ai
Yes, $5 in starting creditSource: vapi.ai
Website in English; the documentation names the German voice “de-DE-KatjaNeural” as an exampleSource: docs.vapi.ai
Sign up online; larger packages via salesSource: vapi.ai
1 Vapi number included at entry levelSource: vapi.ai
Voice providers according to the documentation, including Deepgram, Google, Gladia, Azure, ElevenLabs and OpenAISource: docs.vapi.ai
Vapi Inc., according to the terms of service a company under the laws of Delaware, USA; no postal address is stated thereSource: vapi.ai
VITASAs of 16 October 2026
Phone assistant for companies, regardless of size and industry according to the providerSource: vitas.ai
FLEX: €49 per month with no included volume, then €0.28 per conversation; netSource: telefonassistent.de
Yes, 30 days, without payment detailsSource: telefonassistent.de
Website in GermanSource: vitas.ai
Sign up online for the trial or book a consultationSource: vitas.ai
Individual assistant number as the forwarding destination of your own phone system; alternatively SIP trunkingSource: telefonassistent.de
Calendar for scheduling appointmentsSource: telefonassistent.de
VITAS GmbH, Nuremberg, GermanySource: vitas.ai
voiceOneAs of 16 October 2026
AI phone assistant for small and medium-sized businesses in German-speaking countries; practices, trades, law firms and service providers are namedSource: voice-one.ai
not stated publicly; the plans Basic, Premium and Professional are namedSource: voice-one.ai
Yes, “kostenfreie Startphase” (free start phase)Source: voice-one.ai
Website in German; languages of the assistant not stated publiclySource: voice-one.ai
Sign up online and set it up yourselfSource: voice-one.ai
“Neue Rufnummer in voiceOne oder Ihre bestehende Nummer per Rufumleitung” (a new number in voiceOne or your existing number by call forwarding)Source: voice-one.ai
Google, Outlook, CalDAV, eTermin, DATEV export, REST API and webhooksSource: voice-one.ai
voiceOne UG, Bamberg, GermanySource: voice-one.ai
VokaroAs of 16 October 2026
AI phone assistant for small and medium-sized businesses; trades, practices, real estate and workshops are named, among othersSource: vokaro.net
Vokaro Telefon: €99 per month with 1,000 minutes, then €0.15 per minute; 12-month minimum term; setup €290, waived with annual payment; netSource: vokaro.net
Free demo call and “30 Tage Geld-zurück-Garantie ab Go-Live” (money-back guarantee from go-live); a free trial period is not mentionedSource: vokaro.net
Website in German; number of languages not stated publiclySource: vokaro.net
Arrange an introductory call or start a demo callSource: vokaro.net
not stated publiclySource: vokaro.net
Google Calendar, Microsoft 365, Outlook, THEORG, medatixx, Dampsoft DS-Win, onOfficeSource: vokaro.net
Vokaro, Nuremberg, Germany; legal form not stated in the legal noticeSource: vokaro.net

What Call0 does besides the phone

One account, one knowledge base, every channel. What you teach the phone assistant, the WhatsApp, email and chat assistants know too.

  • 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 →

How we rated

Five points that decide more in daily use than the per-minute price.

  1. Channels

    Does the assistant only answer the phone, or also WhatsApp, email and the website chat with the same knowledge?

  2. Handover to people

    Can a call go to your team with a queue, hold music and opening hours, without the caller dialling again?

  3. Concurrent calls

    How many callers get through at the same time in the entry plan?

  4. Start and setup

    Can you start online today, and who changes the assistant afterwards?

  5. Transparent prices

    Is the price published, and is telephony and the language model included?

  6. German

    Website, product and conversations in German.

The other providers at a glance

What the providers stand for according to their own description. Derived from focus, start or price on their pages.

  • Audelia

    Businesses that want to combine AI with a human phone team

    Source: audelia.com

  • Cognigy

    Large companies with their own contact center

    Source: cognigy.com

  • Doctolib KI-Telefonassistent

    Medical practices that want to use a phone assistant from Doctolib

    Source: info.doctolib.de

  • ElevenLabs Agents

    Teams that build voice agents on a platform themselves and connect telephony themselves

    Source: elevenlabs.io

  • elunos.ai

    Companies with a steady need for minutes that want to start from industry templates

    Source: elunos.ai

  • Famulor

    Companies and agencies that want to start usage-based without a base fee

    Source: famulor.io

  • fonio

    Businesses in German-speaking countries looking for fixed minute packages and a provider in the EU

    Source: fonio.ai

  • HalloPetra

    Trade businesses that want to hand over calls by call forwarding

    Source: hallopetra.de

  • IONOS KI Telefonassistent

    Businesses that want to pay per call instead of per minute and cancel monthly

    Source: ionos.de

  • livestep

    Companies that want to use AI telephony together with a marketing platform

    Source: livestep.ai

  • Ordicall

    Medical practices, MVZ and clinics that want a guided setup

    Source: ordicall.ai

  • Parloa

    Enterprise customer service with a contact center platform

    Source: parloa.com

  • Placetel AI

    Businesses that already use a phone system and want to add the assistant

    Source: placetel.de

  • Retell AI

    Developer teams that want usage-based billing without a base fee

    Source: retellai.com

  • RufLab

    Small businesses that want to start online from their website and test first

    Source: ruflab.com

  • sipgate sona

    Small businesses that want to begin with a permanently free plan

    Source: sipgate.de

  • Synthflow

    Companies looking for an enterprise contract for automated calls

    Source: synthflow.ai

  • Vapi

    Developer teams that combine models and voice providers themselves

    Source: vapi.ai

  • VITAS

    Companies in any industry that want to test for 30 days and get advice on the setup

    Source: telefonassistent.de

  • voiceOne

    Small businesses, practices and law firms that want to set up online themselves

    Source: voice-one.ai

  • Vokaro

    Businesses with industry software such as THEORG or onOffice that want to start with an introductory call

    Source: vokaro.net

How to test two providers

What a fair comparison covers

  • Audience: business users, an internal product team or developers.
  • Total cost: platform, telephony, speech recognition, language model, voice output and add-ons.
  • Operation: monitoring, error handling, phone numbers, data protection and support.
  • Conversation: response time, interruptions, languages and voices.
  • Workflow: integrations, API, outbound calls and approvals for write actions.

How to test two providers

  1. Use the same test scenario and the same knowledge for both.
  2. Build in a correction: “No, I meant next Saturday.”
  3. Interrupt the assistant during a long answer.
  4. Check proper names, numbers and opening hours.
  5. Compare the transcript with the answer that was actually heard.

Monthly cost = base price + additional minutes + telephony + model costs + add-ons + internal operating effort. Only this total belongs in a decision matrix; a price per minute is comparable only when the scope of service is next to it.

Test two providers with the same five real calls before signing a contract. A good assistant fits not only the demo, but also the person who updates the knowledge, traces errors and keeps an eye on costs.

Frequently asked questions

Which AI phone assistant is the best?

For most small and medium-sized businesses we recommend Call0. The assistant is built from your website, Launch already includes 3 concurrent calls, calls can be handed over to your team, and WhatsApp, email and the website chat run in the same account. Teams that develop voice agents themselves are well served by a developer platform.

Which AI assistant covers phone, WhatsApp, email and chat?

Call0 covers all four channels in one account with one shared knowledge base, plus handover of calls to your team and over 500 integrations.

What is the difference between Call0 and fonio?

Both are ready-made AI phone assistants that you can start online. fonio’s entry plan according to its pricing page: Solo: €119 per month with monthly billing, €99 per month with annual billing; 1,000 minutes, 1 concurrent call; net. Call0 Launch: €110 per month, 700 minutes and 3 concurrent calls. Call0 adds handover to your team with a queue, assistants for WhatsApp and email in the same account and over 500 integrations. As of 27 October 2026.

Can an AI phone assistant hand calls over to my staff?

With Call0, yes. The assistant clarifies the request, then the phones of your team ring: with a queue and hold music, 25 seconds per person in turn, opening hours and a rule for when nobody is free, for example a callback.

Which providers publish their prices?

Of 22 providers, 18 state a price on their website: Call0, Audelia, ElevenLabs Agents, elunos.ai, Famulor, fonio, HalloPetra, IONOS KI Telefonassistent, livestep, Ordicall, Placetel AI, Retell AI, RufLab, sipgate sona, Synthflow, Vapi, VITAS and Vokaro. As of 27 October 2026.

Which AI phone assistants can I try for free?

A free trial or starting credit is stated by Call0, Audelia, ElevenLabs Agents, Famulor, HalloPetra, IONOS KI Telefonassistent, livestep, Ordicall, Placetel AI, Retell AI, RufLab, sipgate sona, Vapi, VITAS and voiceOne. Call0 includes 15 test minutes without a credit card. As of 27 October 2026.

How current is the information?

All information was last checked on 27 October 2026. Prices and plans change; the page of the respective provider is always authoritative.

One-to-one comparisons

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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.