localStorage & sessionStorage

Saving & reading data

A simple key-value API that survives page reloads.

localStorage.setItem("theme", "dark");
console.log(localStorage.getItem("theme"));  // "dark"
localStorage.removeItem("theme");

local vs session

localStorage persists across browser restarts; sessionStorage clears when the tab closes. Both only store strings.

Storing objects

Use JSON.stringify() before storing an object and JSON.parse() after reading it back — storage only holds strings.