How do I log in to Messenger on a new device?

To log in to Facebook Messenger on a new device, open the Messenger app or go to the Messenger website and enter the same Facebook account email address, phone number, and password that you already use. If the account is already signed in on another device, Facebook Messenger may ask for a security check, such as a code sent by text, email, or through the Facebook app. If you have two factor authentication turned on, you will need the verification code from your authentication method before the new device will be allowed in. After that, you may be asked whether to save the device for future logins. If you forgot your password, use the password recovery option on the login screen before trying again. If the login does not work, check that the app is updated, the device has a stable internet connection, and the account is not temporarily locked. If you are unsure about any official sign in or recovery steps, look on the current web page for contact information or account help links.