How Glean loads instantly - Glean

This post details the implementation of a novel technique for instant New Tab Page loading by combining Service Workers with Workbox for offline caching of code and resources, redux-persist with relaxed durability for local caching of user preferences in IndexedDB, and a client-side snapshotting of the DOM's HTML persisted to the Service Worker. This allows for immediate display with no JavaScript required for the initial render, avoiding issues like clearing search inputs, improper hydration, and staleness.