SessionStorage

SessionStorage is a component of the Web Storage API that provides a per-tab key-value storage area for the duration of a browsing session. Data stored in sessionStorage persists across page reloads and restores within the same tab, but is cleared when the tab or its browsing context is closed. Each tab typically has its own sessionStorage, and the data is scoped to the same origin, meaning it is not shared with other tabs or windows.

The API consists of setItem, getItem, removeItem, clear, a length property, and key(index) to enumerate keys. Values are stored as strings; to store objects or arrays, you must serialize with JSON.stringify and parse with JSON.parse when retrieving. For example, you can store a token with setItem('token', 'abc123') and later read it with getItem('token').

Lifecycle and scope: SessionStorage lasts for the lifetime of the tab’s session. It is cleared when the tab is closed. It is confined to the origin and is not accessible by pages from a different origin. It is separate from localStorage, which persists across browser sessions.

Usage considerations: SessionStorage is suitable for temporary data needed during a single tab session, such as UI state or non-sensitive tokens that do not need to persist after the tab closes. It is not intended for long-term storage or cross-tab communication. Be mindful that storage quotas vary by browser and that data should be treated as untrusted client-side data.