ElevenLabs vs. Vapi.ai

A detailed feature comparison between the two platforms.

Mar 12, 2025, 3 minutes reading time

Summary

Both ElevenLabs and Vapi.ai are powerful conversational AI platforms designed for building customizable voice agents.
ElevenLabs creates its own TTS and STT models in-house, reducing latency and offering greater control.
Vapi.ai offers an API-native platform with flexibility and scalability, integrating with multiple TTS providers, including ElevenLabs.
Both platforms provide reliable tools for API calls, knowledge base management, and telephony integrations.

Overview

ElevenLabs and Vapi.ai are leading conversational AI orchestration platforms, offering reliable tools for creating customizable voice agents. While ElevenLabs focuses on in-house TTS and STT models for enhanced latency and control, Vapi.ai emphasizes flexibility and scalability with its API-native architecture. Both platforms support extensive language options and provide advanced integration tools, making them suitable for businesses and developers seeking innovative voice AI solutions.

Introduction to ElevenLabs and Vapi.ai

Conversational AI orchestration platforms, like ElevenLabs and Vapi.ai, enable developers to create customizable voice agents. These voice agents now handle customer support calls, train 911 dispatchers, and power new journalistic experiences.

Most platforms combine speech to text (STT), a large language model (LLM), and text to speech (TTS), along with built-in turn-taking and interruption handling, to support natural, human-like conversations. Many companies, like Vapi.ai, partner with other organizations to provide each of these components.

In contrast, ElevenLabs is both a research and product company that creates foundational audio models and offers a packaged solution. This integrated approach allows ElevenLabs to optimize latency by eliminating the need for multiple server calls, providing users with the highest quality TTS and STT in-house.

Feature comparison

For a more in-depth understanding of how the two platforms compare, let’s review their unique features and customization opportunities:

Provider	ElevenLabs	Vapi.ai
Includes an extensive voice library	Includes an extensive voice library with over 5,000 voices across 32 languages and numerous regional accents. Users can design new voices from a text prompt or clone their own.	Integrates with multiple TTS providers, including ElevenLabs, allowing users to select from various voice options.
Latency	Uses the Flash model, which is the fastest, most human-like TTS available. Also has an advantage for end-to-end latency, saving two server calls through in-house TTS and STT.	Operates on a custom real-time audio infrastructure with sub-500ms latency.
Tools & API Calls	Provides server tools to call third-party apps or APIs to fetch real-time information or take action. Also offers client tools to trigger browser events, run client-side functions, or send notifications to a UI.	Provides API-native architecture with extensive configurations and integrations, supporting tool calling to fetch data and perform actions on servers.
Languages	Supports 30+ languages. Allows users to set a custom voice or first message for each language.	Supports over 100 languages, enabling agents to communicate in multiple languages and regional accents.
Concurrency	Concurrency by tier for ElevenLabs base plans is available here. Custom limits are available to handle scale for the largest enterprises.	Scales up and down to handle millions of calls with ultra-low latency interactions.
LLM	Allows users to select from leading models from OpenAI, Anthropic, Google, and DeepSeek or integrate their own custom LLM.	Allows integration with various LLMs, including OpenAI and Anthropic, and supports bringing your own models.
Knowledge Base Management	Allows users to import files, URLs, or plain text to equip their agents with relevant, domain-specific information. Offers a unique vertically integrated RAG for grounding responses in Enterprise data with minimal latency.	Supports integration with external knowledge bases and APIs to provide real-time information during calls.
Telephony Integrations	Offers PCM 8000 Hz or μ-law 8000 Hz sample rates for integration with any provider. For additional information, refer to the Twilio quickstart guide.	Integrates with existing telephony systems, including Twilio, and offers SIP telephony support.
Data Retention	By default, ElevenLabs retains conversation data for 2 years. Users can modify this period to any number of days, unlimited retention, or immediate deletion.	Offers customizable data retention policies, with options for immediate deletion or extended retention periods, ensuring compliance with regulations.
Tracking & Analytics	Allows users to review past recordings, transcripts, and call summaries. Offers custom prompts to tag calls based on internal success criteria and extract data from transcripts.	Provides real-time analytics and call monitoring features, along with automated testing to identify risks before production.

Final thoughts

Based on the feature comparisons above, both platforms offer powerful AI-driven voice solutions.

ElevenLabs provides an extensive voice library, integrated STT and TTS services, and comprehensive language support, making it suitable for diverse applications with low latency. Vapi.ai focuses on offering a flexible, API-native platform with extensive integrations, appealing to developers seeking customizable voice AI solutions.

Your choice between the two will depend on your specific requirements, such as the need for in-house model integration, customization capabilities and latency.

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