When does a PHP session end?

Question

I can't seem to find a definitive answer on the internet, so I'm asking here.

When one uses session_start(); in a .php script and saves some values, when does the session end? So when would those values not be accessible again?

I've found that refreshing the page or stopping the session code-wise would stop it, and a possible time-out would stop the session as well. But what about navigating away from the site and returning a minute later? And closing the browser?

As for the last one, on mobile, what does 'closing the browser' mean? Closing the tab or even minimalising the site?

Answer 1

If your session values are not linked to any cookie, the session will end when the windows browser will be closed.

If your session variable comes from a cookie, the session will end after time specified in the cookie file.

In PHP, sessions work with a cookie of type session. Server-side, the session information is constantly deleted.

To set the lifetime of a cookie in php, you can use the function session_set_cookie_params, before the session_start:

session_set_cookie_params(3600,"/");
session_start();

For ex, 3600 seconds is a one hour, for 2 hours 3600*2 = 7200.

But it's a session cookie, the browser can make it expire by himself, if you want to save longer sessions (like remember login), you need save the data in the server and a standard cookie on the client side.

Navigating away from a site when using cookies will not break the session.