Session storage
Also known as: sessionStorage, per-tab storage
sessionStorage is a small per-tab store web apps use for data that should last only while a tab is open — form steps, temporary state, or a one-visit token. It clears automatically when you close the tab, so it rarely accumulates and almost never needs manual cleanup.
- Per-tab web storage for temporary state
- Clears automatically when the tab closes
- Rarely needs manual cleanup
Tied to a single tab
sessionStorage holds key-value data scoped to one tab and one site. The moment that tab closes, the data is gone — a new tab to the same site starts empty. This makes it ideal for short-lived state like a multi-step form a site does not want to keep.
Because it self-clears, sessionStorage does not pile up the way persistent storage can. It is not a meaningful contributor to a full disk, so there is rarely a reason to target it for cleanup.
Compared with localStorage
The contrast is lifetime: sessionStorage clears on tab close, while localStorage persists until deleted. Both share the same small per-site quota and the same simple key-value model.
You normally never clear sessionStorage by hand. If you do want it gone, clearing a site’s data — via Chrome’s Delete browsing data > Cookies and other site data or Safari’s website-data list — removes it along with localStorage and cookies.