JavaScript: sessionStorage (In-Depth)

sessionStorage is part of the Web Storage API. Like localStorage, it stores key-value pairs, but only for the duration of the page session. When the browser tab or window is closed, the data is cleared.

Basic Usage

sessionStorage.setItem("score", "200");
let score = sessionStorage.getItem("score"); // "200"
sessionStorage.removeItem("score");
sessionStorage.clear(); // Removes all keys for this session
    

Differences from localStorage

• sessionStorage is cleared when the page session ends (tab/window closed).
• Data is NOT shared between tabs/windows.
• Otherwise, API and storage limits are similar.

Data is Stored as Strings

sessionStorage.setItem("user", JSON.stringify({ name: "Bob" }));
let userObj = JSON.parse(sessionStorage.getItem("user"));
    

When to Use sessionStorage

• Temporary data (like wizard progress, tab state, etc.)
• One-time tokens needed for the current tab only
• Data that should not persist after the window is closed