Part 9: Cookie vs. SessionStorage vs. LocalStorage Showdown
📖 Series Navigation: ← Previous Chapter: Redis Distributed State vs. Dapr Virtual Actors | Series Hub Part 9: Cookie vs. SessionStorage vs. LocalStorage Showdown: Network Headers Tax, Tab Isolation & Token Storage Architecture Answer-first: Choose HTTP Cookies (HttpOnly; Secure; SameSite=Strict; Path=/; __Host-) for server-authenticated sessions, SSR edge gatekeeping, and security tokens to neutralize XSS exfiltration. Use sessionStorage for tab-isolated, transient transactional workflows (e.g. multi-step checkout wizards) to prevent cross-tab state collision. Reserve localStorage exclusively for lightweight (<50KB), non-sensitive user preferences (e.g. dark mode, locale) to avoid synchronous main-thread I/O blocking that degrades Interaction to Next Paint (INP). For structured offline caching (>5MB), graduate immediately to IndexedDB/OPFS. ...