Facebook, Messenger, Instagram and Threads went down for users around the world this morning, with many people unable to log in to their accounts for more than an hour.
Parent company Meta says the issues with the sites - first reported about 4am - have now been resolved.
Most people were finding they had been logged out of their Facebook accounts and could not log back in, while Instagram feeds would not load.
From around 5.40am users began to report the sites were working again.
Meta communications director Andy Stone posted to X - formerly Twitter - at around 6.20am that there had been a “technical issue” and it had been resolved as quickly as possible.