Build a Next.js 16 PWA with true offline support

Progressive Web Apps (PWAs) often fail to deliver a truly offline experience, as they typically cache static assets but lack the ability to handle real data and user actions without a network connection. This text explains how to create a Next.js 16 PWA that maintains functionality when offline by using advanced caching strategies, local data storage with IndexedDB, and a synchronization mechanism that updates changes once connectivity is restored. The guide emphasizes moving beyond the basic app shell model to offer true offline support, which allows users to interact with the app seamlessly in low-connectivity situations. Practical examples are given through the construction of a simple todo app that supports offline task management, highlighting the importance of service workers, local storage, and sync logic. The article also addresses common challenges such as service worker updates, HTTPS requirements, iOS limitations, and suggests further enhancements like background sync and conflict resolution to improve user experience.