This comprehensive AR.js tutorial walks you through building a marker-based WebAR experience from scratch. Whether you’re a web developer or AR enthusiast, this guide explains the fundamentals of AR.js, a powerful JavaScript library for Augmented Reality on the web. You’ll learn how to set up your development environment, use markers, integrate 3D models, and deploy your AR experience—all without requiring any app downloads. This tutorial is beginner-friendly and optimized for modern browsers, making it ideal for accessible AR development.
What Is AR.js and Why Use It?
AR.js is an open-source JavaScript library that brings Augmented Reality to the web using WebXR, WebGL, and Three.js. It’s lightweight, efficient, and designed for both desktop and mobile browsers without needing native apps.
Unlike native AR SDKs, AR.js works entirely in the browser and supports both marker-based and location-based AR. This makes it ideal for projects that prioritize accessibility, speed, and low bandwidth environments.
Core Features of AR.js
- Marker-based AR using Hiro and custom markers
- Location-based AR using GPS data
- Seamless Three.js integration
- Works in all major mobile browsers
- Lightweight and fast (60 FPS performance possible)
Prerequisites
Before diving in, make sure you have the following:
- Basic knowledge of HTML and JavaScript
- A code editor (VS Code recommended)
- A smartphone with camera and browser (Chrome or Safari)
- Internet connection to host the files or run via local server
Also Read: 10 Best Free Tools for Building AR Apps: 2025 Guide for Developers & Creators
Step-by-Step Guide: Build Your First WebAR Experience Using AR.js
Step 1: Setup the HTML Boilerplate
Start with a simple HTML document and include the required AR.js and A-Frame libraries.
<!DOCTYPE html>
<html>
<head>
<title>AR.js Tutorial</title>
<script src="https://aframe.io/releases/1.2.0/aframe.min.js"></script>
<script src="https://cdn.rawgit.com/jeromeetienne/ar.js/1.7.2/aframe/build/aframe-ar.min.js"></script>
</head>
<body style="margin: 0; overflow: hidden;">
<a-scene embedded arjs>
<!-- AR content will go here -->
</a-scene>
</body>
</html>
This boilerplate initializes the A-Frame scene with arjs
support.
Step 2: Add a Marker
Now let’s add a default marker (like Hiro) for triggering your AR content.
<a-marker preset="hiro">
<a-box position='0 0.5 0' material='color: blue;'></a-box>
</a-marker>
<a-entity camera></a-entity>
This code displays a blue 3D cube on the Hiro marker. You can print this marker from AR.js Hiro marker.
Step 3: Create a Custom Marker (Optional)
If you want to use your own logo or image:
- Go to the Marker Training tool
- Upload your image and download the
.patt
file - Upload the file to your web server
- Replace the preset code with:
<a-marker type='pattern' url='your-custom-marker.patt'>
<a-sphere color='red' radius='0.3'></a-sphere>
</a-marker>
This shows a red sphere when your custom marker is detected.
Also Read: 10 Best WebAR Tools That Don’t Need App Downloads
Step 4: Add a 3D Model
Instead of primitives, you can load .glb
or .gltf
models into your AR scene.
<a-marker preset='hiro'>
<a-entity
gltf-model="url(model/robot.glb)"
scale="0.5 0.5 0.5"
position="0 0 0">
</a-entity>
</a-marker>
Make sure to host your 3D model properly or use a CDN like Sketchfab or Google Poly (if still available).
Step 5: Test It Locally
Use a local server like:
npx http-server
Or use VS Code Live Server extension. Open the URL on your smartphone, point it at the marker, and watch your content appear.
Step 6: Host Your AR Experience
You can upload your files to platforms like:
- GitHub Pages
- Netlify
- Vercel
- Glitch
Hosting ensures mobile access without requiring downloads or special apps.
Bonus: Add Location-Based AR (AR.js v3)
If you want to render AR objects based on user location:
<a-entity gps-entity-place="latitude: 37.7749; longitude: -122.4194;">
<a-box color="green" scale="2 2 2"></a-box>
</a-entity>
Make sure to enable gps-camera
and location permissions.
Troubleshooting AR.js Issues
Problem | Solution |
---|---|
Marker not detected | Ensure proper lighting, print quality, and contrast |
Camera not working | Check HTTPS and browser permissions |
3D model not loading | Check model URL, format, and compatibility |
AR content laggy | Reduce model size and polygon count |
Best Practices for AR.js Development
- Optimize 3D models for web: use low-poly with compressed textures
- Use secure (HTTPS) hosting for camera access
- Always test on real mobile devices, not just desktop emulators
- Use preloader animations if loading large assets
- Build fallback UIs in case camera access is denied
Also Read: Build AR Without Coding: 10 Best No-Code AR Tools
FAQs
- Can I build AR.js projects without using A-Frame?
Yes, AR.js can also be used with Three.js directly for more control, though A-Frame simplifies development. - Is AR.js compatible with WebXR API?
Yes, newer versions are being adapted to work with WebXR for better device compatibility and performance. - Can I use AR.js with React or Vue?
AR.js is built for vanilla JS, but you can embed its functionality in React/Vue using iframe or web components. - Does AR.js support hand tracking?
No, AR.js currently focuses on marker and location-based AR. For hand tracking, look at 8thWall or WebXR hand tracking APIs. - Is there a way to add sound or audio in AR.js?
Yes, you can embed audio using<a-sound>
in A-Frame and trigger it when markers are detected. - Can I use AR.js without an internet connection?
Yes, as long as all assets are locally hosted. But HTTPS is required for camera access even in local environments. - How do I handle different screen sizes or orientations?
Use A-Frame’sviewport
,camera
, andresponsive
properties to scale content effectively across devices. - Can I animate my 3D models in AR.js?
Yes, if your.glb
or.gltf
model includes animations, A-Frame can play them using theanimation-mixer
component. - What are the limitations of marker-based AR?
It relies heavily on camera alignment, lighting, and print quality. Complex scenes may suffer from tracking jitter. - Is it possible to combine AR.js with geospatial data?
Yes, AR.js has built-in GPS support to trigger AR content at specific coordinates, great for tourism or mapping projects.