Web storage is a feature in web browsers that allows websites to store data locally within a user's browser. It provides two mechanisms for storing data persistently on the client-side:
-
Session Storage:
- Scope: Data stored in session storage is scoped to the current browser tab or window and persists as long as that tab/window is open.
- Usage: It's ideal for storing temporary data that should be available only during the current session.
-
Access:
Accessed via the
sessionStorage
object in JavaScript.
Example:
// Storing data in session storage sessionStorage.setItem('key', 'value'); // Retrieving data from session storage const data = sessionStorage.getItem('key');
-
Local Storage:
- Scope: Data stored in local storage persists even after the browser is closed and reopened. It's available across browser sessions and tabs for a specific domain.
- Usage: It's suitable for storing data that needs to be retained between sessions.
-
Access:
Accessed via the
localStorage
object in JavaScript.
Example:
// Storing data in local storage localStorage.setItem('key', 'value'); // Retrieving data from local storage const data = localStorage.getItem('key');
- Both session storage and local storage use key-value pairs to store data.
-
They only store data in string format, so complex objects need to be serialized (e.g., using
JSON.stringify() and JSON.parse()
). - They provide a simple and easy-to-use way to store small to medium amounts of data on the client-side without the need for server interaction.
- The maximum storage capacity is typically larger for local storage compared to session storage, but exact limits vary across browsers (usually several MBs per domain).
- Data stored in web storage is specific to the domain and protocol (HTTP/HTTPS) of the website.
Web storage is commonly used for storing user preferences, session-specific information, cached data, or any other client-side data that needs to persist across sessions or tabs. However, sensitive information like passwords or tokens should be handled securely and not stored in web storage due to its vulnerability to cross-site scripting (XSS) attacks.