# Your First Barcode Scan {#first-scan}
This tutorial walks you through creating a simple barcode scanner using your device's camera.
## Prerequisites {#prerequisites}
- A web browser that supports camera access (Chrome, Firefox, Safari, Edge)
- A device with a camera
- Basic knowledge of HTML and JavaScript
## Step 1: Set Up the HTML {#step-1-html}
Create an `index.html` file:
```html
Barcode Scanner
Barcode Scanner
Scan a barcode...
```
## Step 2: Initialize Quagga {#step-2-initialize}
Create an `app.js` file:
```javascript
Quagga.init({
inputStream: {
type: "LiveStream",
target: document.querySelector('#scanner-container'),
constraints: {
facingMode: "environment" // Use back camera
}
},
decoder: {
readers: ["code_128_reader", "ean_reader", "upc_reader"]
}
}, function(err) {
if (err) {
console.error("Failed to initialize:", err);
document.querySelector('#result').textContent = "Error: " + err.message;
return;
}
console.log("Scanner ready");
Quagga.start();
});
```
## Step 3: Handle Detections {#step-3-handle-detections}
Add detection handling to `app.js`:
```javascript
Quagga.onDetected(function(result) {
const code = result.codeResult.code;
const format = result.codeResult.format;
document.querySelector('#result').textContent =
`Found ${format}: ${code}`;
console.log("Barcode detected:", code);
});
```
## Step 4: Run It {#step-4-run}
1. Serve the files using a local web server (required for camera access)
2. Open the page in your browser
3. Allow camera access when prompted
4. Point the camera at a barcode
**Note**: Camera access requires HTTPS on non-localhost domains.
## Complete Code {#complete-code}
Here's the complete `app.js`:
```javascript
Quagga.init({
inputStream: {
type: "LiveStream",
target: document.querySelector('#scanner-container'),
constraints: {
facingMode: "environment"
}
},
decoder: {
readers: ["code_128_reader", "ean_reader", "upc_reader"]
}
}, function(err) {
if (err) {
console.error("Failed to initialize:", err);
document.querySelector('#result').textContent = "Error: " + err.message;
return;
}
Quagga.start();
});
Quagga.onDetected(function(result) {
const code = result.codeResult.code;
const format = result.codeResult.format;
document.querySelector('#result').textContent = `Found ${format}: ${code}`;
});
```
## Next Steps {#next-steps}
- [Static Image Scanning](static-image.md) - Decode images without camera
- [Configuration Reference](../reference/configuration.md) - Customize behavior
- [Tips and Tricks](../how-to-guides/tips-and-tricks.md) - Improve results
---
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