LocalStorage
LocalStorage is a web storage API that allows web applications to store key-value pairs locally in a user's browser with no expiration date, persisting data across browser sessions. It provides a simple synchronous interface for storing up to 5-10MB of string data per origin, making it useful for client-side data persistence without server interaction. Unlike cookies, LocalStorage data is not sent with HTTP requests, enhancing privacy and performance for offline or stateful web applications.
Developers should use LocalStorage when they need to persist non-sensitive user data like preferences, form drafts, or application state locally in the browser, particularly for progressive web apps (PWAs) or offline functionality. It's ideal for scenarios requiring simple client-side storage without complex setup, such as remembering user settings, caching small datasets, or maintaining session-like state across page reloads, but should be avoided for sensitive data due to lack of encryption and XSS vulnerabilities.