Facebook iconDifference Between VAPI AI vs RETELL AI Voice AI Platforms
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Difference Between VAPI AI vs RETELL AI Voice AI Platforms

Mar 18, 20254 Min Read
Written by Kiruthika
Difference Between VAPI AI vs RETELL AI Voice AI Platforms Hero

Selecting the optimal AI voice platform has become a critical strategic decision for organizations aiming to enhance customer engagement and operational efficiency in an increasingly competitive market. Two prominent contenders in this space are Vapi AI and Retell AI, each offering unique features tailored to diverse business needs. This comprehensive analysis delves into the strengths and weaknesses of both platforms, providing a detailed comparison to assist in making an informed decision.

What is Vapi AI

Vapi AI is a developer-centric platform designed to empower businesses with customizable tools for building advanced voice AI agents. It caters to enterprises seeking deep customization and flexibility in their voice applications.

                            PROS

                            CONS

Enhanced User Experience

Complex Pricing Structure

Advanced Language Processing

Limited Free Concurrency

Strong Developer Support

Restricted Telephony Integration

Robust Customization Options

Lower Uptime Guarantee

Enhanced User Experience

CONS

Complex Pricing Structure

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What is Retell AI

Retell AI is a platform designed to enhance phone call interactions through advanced AI capabilities, providing features like live transcription and tool calling. It ensures compliance with industry standards by being HIPAA compliant, with SOC 2 Type II compliance in progress.

                            PROS

                            CONS

User-Friendly Interface

Limited Customization for Developers

High reliability

Potential Latency Issues

Flexible Pricing Model

Limited Voice Cloning Capabilities

Comprehensive Feature Set

Limited number of agents that can be deployed

User-Friendly Interface

CONS

Limited Customization for Developers

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Feature Comparison between Vapi AI and Retell AI

Now, we’ll explore the key differences between the basic features of Vapi AI and Retell AI, comparing their capabilities, performance, and suitability for various use cases.

Feature

Vapi AI

Retell AI

Notes

Agent Builder

Single Prompt & Agent Blocks

Single Prompt & Multi Prompt

Retell's multi-prompt system offers more flexibility in conversation design

Custom LLM Support

Yes - Multiple model support

Yes - Multiple model support

Both platforms allow integration with various LLM providers

Multilingual Support

35+ languages

19 languages

Vapi offers broader language coverage

Voice Quality

High-quality TTS

High-quality TTS 

Retell offers additional audio customization

Latency

Sub-second latency

Sub-second latency

Both platforms offer similar performance

Uptime SLA

99.94%

99.99%

Retell offers slightly better reliability

Concurrent Calls

10 free concurrent calls

20 free concurrent calls

Retell provides better free tier capacity

Response Time

Real-time

Real-time

Both platforms offer quick response times

Custom Telephony

Limited to Twilio and Vonage

Supports SIP trunking to any telephony

Retell offers more flexible telephony options

Webhook Support

Yes

Yes

Both support real-time event notifications

Post-call Analysis

Yes 

Yes

Both offer call analysis capabilities

Real-time Monitoring

Yes

Yes

Both provide live monitoring features

Call Recording

Available with transcription

Available with transcription

Both support call recording

Compliance Certifications

HIPAA, GDPR & SOC 2

(HIPAA: $1,000/month additional)

HIPAA, GDPR, SOC 2 Type 1 & Type 2

(All included)

Retell offers more comprehensive compliance coverage

Webcall Support

Yes 

Yes 

Both support web-based calling

Knowledge Base

Supported

Supported

Both offer knowledge base integration

Agent Builder

Vapi AI

Single Prompt & Agent Blocks

Retell AI

Single Prompt & Multi Prompt

Notes

Retell's multi-prompt system offers more flexibility in conversation design

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Why Choose One Over the Other?

When deciding between Vapi AI and Retell AI, consider the following factors:

  • Customization Needs: If your business requires deep customization and has the technical expertise to manage complex configurations, Vapi AI's robust customization options and strong developer support may be advantageous.
  • User-Friendly Experience: For businesses seeking an intuitive interface with comprehensive features and high reliability, Retell AI offers a user-friendly platform with a wide range of functionalities and a higher uptime guarantee.
Suggested Reads- Difference Between VAPI AI vs VOCODE Platforms

Plans and Pricing of Vapi AI and Retell AI

Plan

Vapi AI

Retell AI

Base Rate

$0.05 per minute fixed platform fee

$0.07–$0.31 per minute, depending on selected features

Additional Costs

Extra charges for long prompts; $2.00/month per phone number; Slack support: $5,000/month; HIPAA compliance: $1,000 month

Conversation voice engine API, LLM Agent, Telephony, Knowledge

Base Rate

Vapi AI

$0.05 per minute fixed platform fee

Retell AI

$0.07–$0.31 per minute, depending on selected features

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Which AI is Best For You?

When choosing between Vapi AI and Retell AI, it's essential to align the platform's strengths with your business requirements:

  • Vapi AI is ideal for organizations seeking deep customization and possessing the technical expertise to manage complex configurations. Its robust developer support and extensive language processing capabilities make it suitable for enterprises with specific AI needs. 

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However, businesses should be mindful of its complex pricing structure and additional costs for compliance and support.

  • Retell AI offers a user-friendly interface with a comprehensive feature set, including live transcription, customizable call parameters, and tool calling. Its flexible pricing model and higher uptime guarantee make it a reliable choice for businesses aiming for quick deployment and high reliability. 

While it may have limited deep customization options, it provides sufficient flexibility for most business applications.

What Customers Think About Vapi AI and Retell AI

Customer feedback provides valuable insights into the real-world performance of these platforms:

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Vapi AI

  • "Amazing System that they are building. I had issues on a Saturday night, and received a phone call from one of the technicians Sahil and he helped me through my issue. What dedication. I saw some of the other reviews, and they seem to be related to billings, and stuff that could easily be spoken about. I just wanted to give a shout-out to this guy for his passion and dedication to the project." - Robert Peter 

Retell AI

  • Users appreciate Retell AI's efficiency and natural interactions. One reviewer stated, "We’ve been using Retell to build these voice agents for our customer service, for over a year. It’s so natural, people don’t even realize it’s not a human half the time."
  • Another user highlighted the platform's cost-effectiveness, noting, "Retell AI has no platform fees, meaning you only pay for what matters: the API cost."
Suggested reads- Difference Between VAPI AI vs RASA Voice AI Platforms

In conclusion, both Vapi AI and Retell AI offer valuable features for enhancing voice interactions. Your choice should depend on your organization's specific needs, technical capabilities, and budget considerations. For businesses requiring deep customization and possessing technical expertise, Vapi AI may be the preferred choice. 

Conversely, for those seeking a user-friendly platform with comprehensive features and flexible pricing, Retell AI stands out as a compelling option.

Author-Kiruthika
Kiruthika

I'm an AI/ML engineer passionate about developing cutting-edge solutions. I specialize in machine learning techniques to solve complex problems and drive innovation through data-driven insights.

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