How to Scan a Barcode with Your Webcam — In the Browser

To scan a barcode with your webcam, open Zro7 QR & Barcode Scanner, allow camera access, and point the code at the viewport. ZXing decodes it in real time and prints the payload — for QR, WiFi, vCard, EAN, UPC, Code 128, Code 39, Data Matrix, and more.

How it works under the hood

1. navigator.mediaDevices.getUserMedia({ video: true }) opens the camera.
2. The video stream is drawn to a hidden <canvas> at ~30 FPS.
3. @zxing/browser runs pattern detection on each frame in a Web Worker.
4. First successful decode → payload is displayed; camera stays live so you can scan more.

Front vs rear camera

On mobile, Zro7 requests the rear camera (facingMode: 'environment') because it's the only one that focuses close enough to read a barcode. On laptops there's only the front cam — hold the code steady 15–20 cm away.

Formats supported

• QR (all versions), Data Matrix, Aztec, PDF417.
• EAN-8, EAN-13, UPC-A, UPC-E.
• Code 39, Code 128, Codabar, ITF-14.

Why local scanning matters

A QR can encode a WiFi password, a Bitcoin address, or a login OTP. Any 'online QR scanner' that uploads your image sees that data. In-browser scanning keeps it in the tab.

Steps

1. Open QR & Barcode Scanner.
2. Grant camera permission.
3. Point at the barcode; decoded payload appears within a second.
4. Copy the result or scan another.