Cookies vs localStorage vs sessionStorage — JS Technical Interview Questions & Answers

Size, lifetime and server-visibility differences.

Cookies vs localStorage vs sessionStorage

  • Cookies vs localStorage vs sessionStorage (js) is a JS topic. In plain words you use it for remember theme in the browser. Don’t start with a slogan — start with that picture.
  • Smallest example: localStorage.setItem('theme', 'dark'). Type it, run it, and say what you see. If you can do that from memory, you know Cookies vs localStorage vs sessionStorage (js).
  • From the example next to this theory: Size, lifetime and server-visibility differences.
  • Trap: storing passwords in localStorage. Fix that before you talk about advanced JS.
  • Viva: what is Cookies vs localStorage vs sessionStorage (js)? Then show localStorage.setItem('theme', 'dark'). Then name the trap.

Technical Interview Tip: What is Cookies vs localStorage vs sessionStorage (js)? Show this: localStorage.setItem('theme', 'dark'). Trap: storing passwords in localStorage.

Code Examples for Cookies vs localStorage vs sessionStorage

Cookies vs localStorage vs sessionStorage — working example

// Browser:
// document.cookie = "theme=dark; Max-Age=86400; Path=/; SameSite=Lax";
// localStorage.setItem("theme", "dark");
// sessionStorage.setItem("draft", "hello");

// Runnable stand-in:
const jar = { theme: "dark" };
const store = new Map([["theme", "dark"]]);
console.log(jar.theme, store.get("theme"));
store.delete("theme");
console.log(store.has("theme"));

Cookies vs localStorage vs sessionStorage — cookies go to the server; localStorage persists; sessionStorage lasts for the tab.

How to Explain Cookies vs localStorage vs sessionStorage to an Interviewer

What is Cookies vs localStorage vs sessionStorage (js)?

Used for remember theme the browser Not just the heading

Give one small example of Cookies vs localStorage vs sessionStorage (js).

localStorage.setItem('theme', 'dark') Size, lifetime and server-visibility differences

What mistake do beginners make with Cookies vs localStorage vs sessionStorage (js)?

storing passwords in localStorage Show the fix

Where do you use Cookies vs localStorage vs sessionStorage (js)?

the browser remember theme