These tips will help you secure your Facebook account:
Refresh your password. If you have been using the same password for a while, it is highly recommended to change it. The new one should be strong and unique, and should not have been used in the past. Do not share it with anyone. Try to change your password every 6 months. If you are worried about remembering it, you can use a password manager.
Enable two-factor authentication (2FA). You can do this directly from your account settings using these steps:
Computer
Security and Login>
Two-factor authentication>
Use two-factor authentication
iOS
Settings & Privacy>
Password and Security>
Two-factor authentication>
Use two-factor authentication
You will be able to choose the backup step of your choice, and can add more than one in order to give yourself more flexibility and security:
SMS verification code
Authenticator app
Security key
Log out of devices you do not use. Remember to sign out of Facebook if you are not on your primary personal device. This not only includes public computers, but also extends to a friend or relative's device. Here's how:
Computer
Go to Security and Login>
Where You're Logged In on your computer,
iOS-iPhone
Settings & Privacy>
Account>
Password and Security>
Where you're logged in on an iPhone or iPad.
This feature will list the types of devices you are signed into, as well as dates and locations.
Check third-party access. Be careful before giving third-party apps or websites access to your Facebook account. You should remove access for those you no longer use or trust. You can review them in your account settings under:
Security & Privacy>
Permissions>
(iOS) Apps and Websites
(Computer) Settings>Apps and Websites
Set up extra security measures. By turning on these features, you can both reduce your chance of getting hacked and increase your odds of account recovery.
Trusted contacts— This is a list of 3-5 people who can help you recover your account if it's been hacked. As a trusted contact, they can send you a URL that will give you access to a special security code. You must then transmit this code back to them over the phone or face to face.
Unrecognized login alerts— These alerts will inform you of any login from an unfamiliar location or browser, and will allow you to reset your password in order to secure your account. You can receive Facebook notifications and/or email alerts.
Alternate email address— With an alternate email you can log in and reset your password easily; make sure this account has a strong and unique password. You can add it to your Facebook under Settings & Privacy>Personal and Account Information>Contact Info (iOS) or Settings>General>General Account Settings>Contact (computer).