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Add conversational agents to your web, mobile or telephony in minutes. Our realtime API delivers low latency, full configurability, and seamless scalability.
Summary
- Both ElevenLabs and Vapi.ai are powerful conversational AI platforms designed for building customizable voice agents.
- ElevenLabs also creates its own TTS, STT, and turn-taking models that are consistently rated #1 across benchmarks and evals, reducing end-to-end latency and offering greater control over the full audio pipeline.
- Vapi.ai offers a modular, API-native platform that gives users the flexibility to integrate with different providers, including ElevenLabs, at the expense of latency and conversation quality.
- Both platforms support visual workflow builders, knowledge base management, telephony integrations, custom tooling, and text-based chat in addition to voice.
Overview
ElevenLabs Agents and Vapi are both platforms for building voice agents, but they’re optimized for different priorities. ElevenLabs Agents is a vertically integrated, enterprise-ready stack featuring in-house models - Speech to Text (STT), turn-taking, and Text to Speech (TTS) are designed to work together in one co-located system for consistently low latency and high-quality conversations, with built-in workflows, testing, analytics, and security/compliance controls.
Vapi is a modular agent orchestration layer that prioritizes flexibility by giving teams the option to mix and match providers across the voice stack. It’s great for experimentation, although a multi-vendor setup can introduce integration overhead and added latency.
Both support multiple languages, deployments and integrations. The key difference lies in whether you want a single, end-to-end stack optimized for consistent production performance and control (ElevenLabs) or a modular architecture optimized for flexibility (Vapi).
Introduction to ElevenLabs vs Vapi
Agent platforms like ElevenLabs and Vapi 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 STT, a large language model (LLM), and 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:
| Feature | ElevenLabs | Vapi.ai |
|---|---|---|
| Voice Library | Includes an extensive voice library with 10,000+ voices across 70+ languages and many regional accents. Users can design new voices from a text prompt or even clone their own.. | Integrates with multiple TTS providers, including ElevenLabs, allowing users to select from various voice options. |
| Latency | Significantly lower end-to-end latency (sub 300ms) via co-location of models. | When paired with Groq to optimize inference speeds, it can achieve sub-500ms latency. |
| Built-in System Tools | End call, Language detection & auto-switch, Agent transfer, Transfer to human, DTMF send (for IVR navigation), Skip turn, Voicemail detection | Transfer call, End call, Send SMS, DTMF send & receive user input |
| Tools & API Calls | Four tool types: 1. Client Tools (browser/app-side) 2. Server Tools (webhook to your API) 3. MCP tools (Model Context Protocol servers with fine-grained approval controls) 4. System Tools (built-in actions like call transfer, voicemail detection, language detection, end call). |
Supports function tools (server-side via webhook/Server URL), MCP servers, and built-in system tools. Also offers a CLI for terminal-based management and testing. Custom tool responses can be used to extract variables for analytics grouping. |
| Multilingual | Automatic language detection, voice switching, and mid-conversation adaptation. No manual configuration. 70+ languages that support 90% of the global population out-of-the-box. | Language capabilities vary by provider choice. Requires explicit configuration, and programmatic voice switching. |
| Concurrency | Concurrency limits are set by plan tier, with custom limits available for enterprise. Burst pricing allows temporary scale beyond plan limits. | Default concurrency of 10 for standard accounts. Enterprise plans offer unlimited concurrency with reserved capacity. Concurrency can be increased on request. |
| LLM | Allows users to select the latest frontier LLMs, including those from Anthropic, OpenAI, Google, etc. Supports an LLM Cascading fallback mechanism to improve reliability. | Allows integration with various LLMs, including OpenAI and Anthropic, and supports bringing your own models. |
| Knowledge Base Management | Upload files, URLs, or plain text directly, or organize them into folders. Vertically integrated RAG co-located with the speech pipeline for minimal retrieval latency. Knowledge base documents can be reused across multiple agents and scoped per workflow node. | Manual configuration and explicit prompting required. Files must be limited to 300KB for optimal performance. Must connect external RAG systems (Pinecone, etc.) for advanced use. |
| Telephony Integrations | Native Twilio integration, SIP trunking, plus integrations with Genesys, Vonage, Telnyx, and Plivo. Supports PCM 8000 Hz or μ-law 8000 Hz for any provider. Batch outbound calling via API. | Integrates with existing telephony systems, including Twilio, and offers SIP telephony support. |
| Chat/Text Mode | Agents can process both spoken and written inputs and respond in real time across voice and text channels. WhatsApp integration for both inbound/outbound voice and text conversations. | Chat API with streaming and non-streaming modes, OpenAI-compatible endpoints, session management, SMS chat, and a web widget. |
| Data Retention | Configurable retention: any number of days, unlimited, or immediate deletion. SOC 2, HIPAA, and GDPR compliance. EU Data Residency and Zero Retention modes. | Configurable artifact plans for recording, logging, and transcripts. HIPAA mode with zero data retention option. PCI compliance for payment data. SOC 2 certified. Custom cloud storage (S3, GCS, Azure, Cloudflare R2). |
| SDKs & Deployment | JavaScript, Python, Swift (iOS), Kotlin (Android), React Native SDKs. Pre-built React UI component library (shadcn-based). Embeddable web widget. WebSocket API for custom implementations. | JavaScript, Python, and other client SDKs. Web SDK with embeddable voice widget. CLI tool for terminal-based management. Server URL webhook pattern for advanced integrations. |
| Tracking & Analytics | Review past recordings, transcripts, and call summaries. Custom prompts to tag calls, extract data, and score against internal success criteria. Real-time monitoring dashboard. Version control for agents. Built-in agent testing with conversation simulations. | Provides real-time analytics and call monitoring features, along with automated testing to identify risks before production. |
| Pricing Model | Credit-based plans bundled with the broader ElevenLabs platform (including TTS, STT, and creative tools). Enterprise custom pricing available. | $0.05/minute platform fee plus at-cost pass-through for all provider costs (STT, LLM, TTS, telephony). Volume discounts available for enterprises. |
Final thoughts
Both platforms have evolved substantially and offer powerful AI-driven voice solutions, although focus on different types of builders.
ElevenLabs delivers a vertically integrated ElevenAgents built on industry-leading TTS and STT models developed in-house. By co-locating speech recognition, turn-taking, reasoning, and voice synthesis in a single stack, teams get consistently lower end-to-end latency, finer control over voice quality, and more natural conversations in production.
Beyond core voice performance, ElevenLabs offers visual workflows, built-in testing and analytics, chat mode, WhatsApp deployment, and MCP support - making it a comprehensive, enterprise-ready platform. The result is faster time to value and predictable performance, without the complexity and risk of managing multiple vendors or stitching together disparate tools.
Vapi.ai focuses on offering a modular, API-native orchestration layer with numerous integrations, appealing to developers seeking flexibility at the cost of performance.
The right choice comes down to what you want to optimize for. If consistent low latency, best-in-class voice quality, and an end-to-end platform you can run in production with confidence matter most, ElevenLabs is the stronger fit. If your priority is maximum flexibility to assemble and swap providers across a modular voice stack, Vapi is designed for that approach.
