If you are not sure which device you were on, just scroll down through the list of devices then select "Log Out of All Sessions." This will log you out of all your sessions, even your authorized devices, so keep in mind that you will have to re-authorize your devices again.
For mobile Facebook users, click here to see here's our full guide.
4. Prevent others from posting on your Timeline
Sometimes, you just want some peace and quiet and you don't want your friends putting chatter on your Facebook "wall." Maybe your birthday is a secret and you don't want anyone greeting you on your Facebook Timeline for everyone to see.
To do this on desktop Facebook, go to your "Settings" page again then choose "Timeline and Tagging" on the left column. To prevent anyone from posting stuff on your Timeline just click "Edit" on the "Who can post on your timeline" section and set it to "Only Me." This will prevent your friends from embarrassing you any further.
You could also turn off automatic post tagging in this section. This will let you review the posts your friends tag you in before they appear on your Timeline.
For more Timeline and Tagging tips, check this article out.
5. Hide notifications for certain posts
Here's an easy tweak. If you were tagged in a friend's post, you will get notifications each time someone likes or comments on that post, even from non-friends. If it gets a bit overwhelming and you don't particularly care for what everyone else has to say, you could turn off notifications for any post.