qs is a query string parser and stringifier with support for nesting and arrays. It allows you to parse URL query strings into JavaScript objects and conversely, stringify JavaScript objects into URL query strings. It supports advanced use cases like nested objects, arrays, and delimiters customization, making it ideal for complex data structures in URLs. Widely adopted and well-maintained, qs is a reliable choice for handling query parameters in your Node.js or browser-based JavaScript applications.