Browser Storage

localStorage lets a web page store small amounts of data in the browser, which persists even after the page is closed and reopened.

localStorage.setItem("username", "Ada");
console.log(localStorage.getItem("username"));
localStorage.removeItem("username");

Common mistakes

• localStorage only stores strings — storing an object requires JSON.stringify() first, and JSON.parse() when reading it back.
• Never store sensitive data (passwords, tokens) in localStorage — any script running on the page (including from an XSS attack) can read it.