Facebook, Messenger, Instagram and Whatsapp appear to be suffering major problems, with many unable to access their sites.
According to outage tracking website DownDetector, problems began to be reported by people unable to access the sites from about 1am NZT.
Users also report that Instagram has inaccessible since the same time, as has Facebook's messaging app Messenger.
Facebook said through its Twitter account that "we're aware that some people are currently having trouble accessing the Facebook family of apps.
"We're working to resolve the issue as soon as possible."
Instagram also tweeted about the outage, Tweeting "we're aware of an issue impacting people's access to Instagram right now.
"We know this is frustrating, and our team is hard at work to resolve this ASAP."
Instagram has not issued a message through Twitter.
Many people took to Twitter as their only alternative, with some making fun of the inevitable migration.