ZXING
ZXING is a multi-format library for barcode processing. With it, your app or website will be able to generate and recognize all types of 1D and 2D codes, including QR.
ZXing is written in Java and is most commonly used for Android, but can be ported to other languages and platforms. If you want to use QR codes to improve your service and user experience, for marketing or other purposes, this library will be useful.
ZXing is most often used for Android applications. Universal Barcode Scanner, which can be downloaded on Google Play, is a project of the library's developers. At the same time, it has modules for iPhone, C++, Objective-C, TypeScript, Python, PHP, and so on. This means that you can add a scanner not only to an app but also to a website.
ZXing understands all types of 1D barcodes, including QR and more original types of 2D codes, such as Data Matrix and PDF 417. It can decode both their images and links to them. The library also contains tools for the reverse procedure - encoding data for further recognition.
The ZXing API is easy to install and use in a project. It is free software that you can use for your tasks as you want. Or go to the project's Github page and find ready-made solutions for specific tasks there.
If you want your app or website to be able to recognize and generate QR and other barcodes, ZXing will help you. It is the most popular library for this purpose for Android projects and beyond. ZXing is very easy to integrate, especially when compared to the comfort you can provide to your users.