html5-qrcode is a client-side JavaScript library that enables QR code and barcode scanning directly in a web browser, processing live video from a device camera or decoding codes from uploaded image files without any server-side involvement. The library handles real-time scanning from continuous camera feeds with adjustable frame rates and scanning regions, while also supporting file-based decoding for static images.
The scanner offers configurable behavior through runtime settings, allowing developers to adjust scanning speed, viewfinder region, aspect ratio, and restrict decoding to specific 1D or 2D code formats. It provides callback-driven result handling for successful code detection, scan failures, and video stream errors, with automatic scan termination after a successful read to prevent redundant processing. Camera controls include inline switching between available cameras, torch and zoom adjustment during scanning, and the ability to capture high-resolution video for small or distant codes.
The library supports both camera and file scanning modes, which can be configured independently or combined into a single interface. It includes a multilingual interface system for displaying the scanner in languages other than English, and provides programmatic control to stop scanning sessions and clean up camera resources on demand.
