Web storage in JavaScript allows you to store data in the browser. LocalStorage keeps data even after the browser is closed, while SessionStorage keeps data only for the session. Both are key-value storage solutions for client-side data.

This blog explains how to use LocalStorage and SessionStorage with examples.

⭐ 1. LocalStorage vs SessionStorage

Feature	LocalStorage	SessionStorage
Storage Limit	~5MB	~5MB
Lifetime	Permanent (until cleared)	Session (until tab closed)
Shared Across Tabs	Yes	No
Accessible By JS	Yes	Yes

⭐ 2. Storing Data

LocalStorage

localStorage.setItem("username", "Sagar");
localStorage.setItem("age", "22");

SessionStorage

sessionStorage.setItem("username", "Sagar");
sessionStorage.setItem("age", "22");

⭐ 3. Retrieving Data

let username = localStorage.getItem("username");
let age = sessionStorage.getItem("age");
console.log(username, age); // Sagar 22

⭐ 4. Removing Data

localStorage.removeItem("age");      // remove a single item
sessionStorage.clear();              // remove all session storage items

⭐ 5. Storing Objects

LocalStorage and SessionStorage store only strings, so objects must be stringified.

let user = { name: "Sagar", age: 22 };
localStorage.setItem("user", JSON.stringify(user));

let retrievedUser = JSON.parse(localStorage.getItem("user"));
console.log(retrievedUser.name); // Sagar

⭐ 6. Practical Example

Save a user preference:

// Save theme
localStorage.setItem("theme", "dark");

// Retrieve theme on page load
let theme = localStorage.getItem("theme");
document.body.className = theme;

⭐ 7. Why Use Web Storage

Store user preferences without server requests
Maintain login sessions or temporary data
Faster than cookies (larger storage, simpler API)
Works entirely on client-side

⭐ Conclusion

LocalStorage and SessionStorage are simple and powerful ways to store data in the browser. They help improve performance, user experience, and maintain client-side state efficiently.

📌 Citations

🔗 View other articles about Javascript:
https://savanka.com/category/learn/js/

🔗 External Javascript Documentation:
https://www.w3schools.com/js/

JavaScript LocalStorage And SessionStorage Explained