This is still a very manual process, but it’s useful if you logged in somewhere and can’t physically logout from that device. Anyone else will have to sign in again with a password.
If you click the Sign out all other sessions button, only you will be able to access your Gmail account again. If you click on that, it will open a new window showing when you account was accessed by type (browser, IMAP, SMTP, etc) and by IP address/location. If you go to Gmail and scroll all the way to the bottom, you will see Last account activity: x minutes ago and a link called Details. You can log into Gmail on another computer and then sign out all other sessions. Luckily, there is one feature in Gmail that helps with this type of problem. Now what? Technically, that person can just go to Gmail and see all your emails. Let’s say you logged into your Gmail account at a friends house and forgot to logout before leaving.
In this article, I’ll try to walk through the different things I do in order to make sure my account can’t be accessed by anyone else. Unfortunately, there is no perfect solution to this problem. I’ve seen it happen so many times in hotels and apartment complexes where I go to Gmail in the browser and it loads up someone else’s Gmail account! Lucky for them, I’m not a hacker or an evil person otherwise I could theoretically access lots of sensitive information about that person.