Best Open Source Retell AI Alternative in 2026
Last Updated: August 24, 2026
Retell AI is a voice AI platform built for teams that want their AI agents to sound like real people on the phone, not robotic menu systems.
You build agents using a visual flow builder or simple prompts, then connect them to knowledge bases, CRMs like Salesforce and HubSpot, and calendars, so agents can look things up and take real actions mid call.
The best alternative to Retell AI is 
LiveKit
LiveKitOpen-Source Real-Time Video, Audio & AI Platform.
So, here are the 1 best alternatives to Retell AI:
LiveKit is a complete real-time communication platform that uses WebRTC technology to enable low-latency audio, video, and data exchange between users and AI agents. Unlike traditional communication tools, LiveKit is built specifically for developers who want to create custom real-time experiences.
The platform consists of several parts: the open-source LiveKit server that handles media routing, client SDKs for all major platforms, and LiveKit Cloud for managed hosting. It uses a Selective Forwarding Unit (SFU) architecture, which means it can efficiently handle many participants without heavy server processing.
LiveKit is especially strong for AI applications. It can connect voice agents to phone systems, enable real-time transcription, and support multimodal AI that can see and hear simultaneously. Whether you want to build a simple video chat or a complex AI assistant, LiveKit provides the foundation you need.