You can improve the security of your Facebook account by getting an alert when someone tries logging in from a device or web browser we don’t recognize. These alerts will tell you which device tried logging in and where it’s located.
Go to Get alerts about unrecognized logins and click Edit.
Choose where you want to receive your alerts, such as from your email account or with a Facebook notification from a recognized device.
Click Save Changes.
After you start getting alerts about unrecognized logins:
When you receive a login alert, you can tell us if you recognize the login activity by clicking or tapping This was me.
If you don’t recognize the login activity, click or tap This wasn’t me and we’ll help you reset your password and secure your account.
You can save a device or browser to your list of trusted browsers or recognized devices. This way, you won’t get alerts about the computer or mobile device you usually use to log into Facebook. Don’t choose this option if you’re using a public computer (such as one in a library or cafe).