pdf-lib

`pdf-lib` is a robust and actively maintained JavaScript library designed for creating and modifying PDF documents in any modern JavaScript environment, including Node.js, browsers, Deno, and React Native. Currently at version 1.17.1, it receives frequent minor and patch releases, with major versions introducing significant architectural changes. A key differentiator of `pdf-lib` from many other open-source PDF libraries is its comprehensive support for *modifying* existing PDF documents, not just creating new ones. Its features include drawing text, images, and vector graphics, embedding fonts (with UTF-8 and UTF-16 support), managing pages (add, insert, remove, copy), creating and filling forms, and setting/reading document metadata and viewer preferences. The library is written in TypeScript, providing excellent type support for its users.