Build Browser-Based Low-Latency Conversational AI Avatars with Three.js and React

By
Convai Team
March 24, 2026

Traditionally, creating your very own high-fidelity virtual human or even AI avatar has been locked behind a massive hardware wall. If you wanted to run a real-time AI character with realistic animations and complex logic, you usually needed a high-end GPU, a powerful desktop system, and a heavy game engine like Unreal Engine or Unity. This created a significant friction point for users who just wanted to interact with an AI assistant or a virtual guide without downloading a multi-gigabyte application.

The solution lies in the browser. By moving the experience to the web, we can reach users on any device, from a high-end workstation to a standard smartphone. We achieved this much earlier with Avatar Studio and Convai Sim, both of which are no-code tools that allow you to choose from a rig of metahumans and various environments to build your own AI avatar led experiences directly in the browser.

However, with this alternate method, creating 3D AI avatars on the web is just as flexible and enables more use-cases, and in this guide, we will show you how to leverage the Convai Web SDK to bridge the gap between web performance and cinematic quality.

Check out the video below to get started:

Web vs. Native Game Engines: Why Choose the Browser?

When deciding between a native game engine (like Unreal Engine) and a web-based setup (Three.js), it usually comes down to a choice between graphical ceiling and accessibility.

Native Game Engines (Unreal/Unity)

  • Pros: Highest possible fidelity, complex physics, and massive world support.
  • Cons: High friction. Users must download large builds; hardware requirements often exclude mobile or low-end laptop users.

Web-Based (Three.js/React)

  • Pros: Zero friction. Users can easily build AI avatars on your browser that load instantly via a URL. It is cross-platform by default and significantly easier to maintain for e-commerce or marketing sites.
  • Cons: Graphical limitations compared to Ray-Traced native environments. However, with the advent of WebGPU, this gap is closing rapidly.

If your goal is widespread adoption and seamless user onboarding, the web is the clear winner. Easy AI avatars for web deployment allow you to reach your audience where they already spend their time: in the browser.

High-Impact Web Use Cases

AI characters on the web are not just for games; they are powerful tools for conversion and engagement.

  1. Leadership Training Coach: A virtual mentor that simulates difficult management conversations, providing executives with a safe space to practice conflict resolution and empathetic communication.
  2. SaaS Onboarding: A virtual guide that walks a new user through a complex dashboard, answering questions about features as they explore.
  3. Sales Roleplaying Avatars: Dynamic AI prospects that sales teams can use to practice handling objections and closing deals in a realistic, low-stakes environment directly in their browser.
  4. 24/7 Educational Tutors: High-fidelity tutors that can help students with homework through a simple web link, providing a low-stakes environment for learning.

Read Also: Bring Your Unity Characters to Life: A Quick Setup Guide for Interactive Conversational AI

The Technical Blueprint: How to Build

Building AI characters for the web involves a structured pipeline. We use React Three Fiber (R3F) to handle the 3D rendering and the Convai Web SDK to handle the intelligence and voice.

Phase 1: Project Initialization

We start by setting up a modern React environment optimized for performance. We use Vite for its lightning-fast build times and TypeScript for robust type safety. 

For a deeper dive into npm package requirements, refer to the Convai Web SDK Installation Guide.

# Create the React starter with Vite
npm create vite@latest . -- --template react-ts
# Install core dependencies
npm install three @types/three @react-three/fiber @react-three/drei convai-web-sdk

Phase 2: Setting up the Canvas

In your app.tsx file, we initialize the Three.js Canvas. To ensure the highest possible quality, we attempt to use WebGPU, falling back to standard WebGL if the user's browser does not support it. This ensures that creating 3D AI avatars on the web is easy with maximum compatibility across different devices.

// Initializing the Canvas with WebGPU support
<Canvas 
  dpr={1} 
  camera={{ position: [0, 1.6, 3.5], fov: 10 }} 
  gl={{ antialias: true }}
>
  <color attach="background" args={['#000000']} />
  <Experience />
</Canvas>

Phase 3: 3D Model Optimization

Web-based 3D requires extreme optimization. Large GLB files can cause long load times and stuttering animations. Once you have exported your character (such as a Reallusion CC5 model), you should optimize it using GLTF-Transform. This tool compresses textures and streamlines the geometry for the web.

# Optimize the model and generate a React component
npx gltfjsx character.glb --transform --types

Phase 4: Connecting the AI Client

Now we connect the character to the Convai API. This is handled through the useConvaiClient hook, which manages the persistent WebRTC connection. This is the brain of your digital human.

import { useConvaiClient, ConvaiWidget } from "@convai/web-sdk/react";

function App() {
  const convaiClient = useConvaiClient({
    apiKey: "your-api-key",
    characterId: "your-character-id",
    endUserId: "user-uuid", // Optional: enables memory & analytics
  });

  return <ConvaiWidget convaiClient={convaiClient} />;
}

Phase 5: Implementing NeuroSync Lip-Sync

Lip-sync is the most technically demanding part of the build. Convai's NeuroSync provides a callback of blend shape data at 60 frames per second. We implement a useFrame loop that reapplies the AI's lip-sync data after the animation mixer has updated. This ensures the mouth movements always take priority over the body's idle sway.

Phase 6: Adding Head and Eye Tracking

To make the AI feel truly present, it should maintain eye contact with the user. We implement a head-tracking hook that calculates the vector between the character’s head bone and the camera position. This ensures that when the user moves their camera, the AI tracks them with its gaze.

This was a quick summary of how you can go about setting up your AI character project on the browser. We recommend you to watch the full tutorial for a much deeper understanding, and also visit our documentation for more clarification.

Advanced Interactive Scenarios

Scenario 1: The E-commerce Fashion Stylist

  • Character: Sophia, a chic and knowledgeable fashion expert.
  • The Setup: Place Sophia in a 3D showroom using R3F. Integrate a product catalog into her Convai knowledge base.
  • The Interaction: A user can say, "Show me something that goes with these boots." Sophia will see the boots via the multimodal API, suggest a matching jacket, and change her facial expression to one of genuine excitement as she explains the pairing.

Scenario 2: The Virtual Museum Curator

  • Character: Marcus, an elderly and wise historian.
  • The Setup: A web-based VR experience (WebXR) where Marcus stands in a gallery of 3D-scanned artifacts.
  • The Interaction: Users can ask Marcus deep, philosophical questions about the origins of an artifact. Because Marcus has long-term memory, he can remember if a user has visited before and say, "Welcome back, we were just discussing the Bronze Age yesterday."

Scenario 3: The SaaS Technical Assistant

  • Character: Jarvis-lite, a sleek and professional UI guide.
  • The Setup: A floating 3D avatar that lives in the corner of a complex web application dashboard.
  • The Interaction: Instead of searching for a help document, the user simply asks, "How do I export my data as a CSV?" Jarvis-lite not only answers but uses his head tracking to look at the specific button on the dashboard the user needs to click.

Watch our Latest Video: Add Conversational AI to MetaHuman, Reallusion and more | Convai UE Plugin Quick Setup Guide

Frequently Asked Questions (FAQs)

Q: Is it really possible to run high-quality AI characters on mobile browsers?

Yes. By using the transform flag during the GLTF export and leveraging the Convai Web SDK’s efficient WebRTC streaming, you can easily build AI avatars on your browser that perform flawlessly on modern smartphones.

Q: Do I need to manually animate every emotion for my AI characters?

No. Convai handles dynamic emotions automatically. You simply set an initial state (like Happy or Neutral), and the character’s expressions will shift naturally based on the tone of the conversation.

Q: How do I handle users without high-end GPUs?

The boilerplate code we provided includes a fallback to standard WebGL. This ensures that even if WebGPU is unavailable, the user still gets a functional, interactive experience.

Q: What makes creating 3D AI avatars on the web easy with Convai compared to other platforms?

Convai provides a unified Web SDK that handles the heavy lifting of speech-to-text, LLM processing, and real-time lip sync via NeuroSync, allowing you to easily build AI avatars on your browser without complex backend infrastructure.

Q: Can I integrate easy AI avatars for web marketing into existing React projects?

Absolutely. The Convai Web SDK is designed specifically for React and Three.js environments, meaning you can drop conversational AI components into any existing web project with minimal configuration.

Q: Is real-time lip sync supported for all types of 3D models?

Yes. Convai supports ARKit, MetaHuman, and custom blend shape mappings, making it the most versatile solution for creating 3D AI avatars on the web with high-fidelity facial animations.

Join the Convai Community

Now that you know how creating 3D AI avatars on the web is easy with Convai, it is time to start building your own.

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