After using an online service like e-banking, how do you end the session safely — and why isn't closing the tab enough?

Log out through the service's own "Logout" button (never just close the window), then clear the browser cache.

Authentication doesn't end when the page disappears — it ends when the session is explicitly torn down, so how you leave matters as much as how you arrive:

• Use the real logout function ("Logout" / "Abmelden" / "Beenden"). Just closing the window or tab can leave the session alive; the session cookie may still authenticate whoever opens the browser next.
• Clear the browser cache after each session, so cached pages, form fields, or tokens aren't left behind for the next person on that machine.
• Keep other sites closed during the session (the same rule as safe login): a malicious tab open alongside can try to ride your still-authenticated session.

Why it matters most on shared machines: on a public or family computer, a forgotten logout simply hands the next user a live, logged-in account — no password needed. The tab looked closed; the session wasn't.

Tip: Treat logout as locking the door behind you — closing the tab is just walking away and leaving it open.

Go deeper:

• Session hijacking — Wikipedia — why a live session cookie is worth stealing.