According to users, Facebook, Instagram, and WhatsApp are back up and running after being down for more than six hours.
Some services, however, are still not fully operational; for example, Instagram is still having trouble updating new posts.
"We apologize to the people and businesses who rely on us all over the world," Facebook said in a statement. "We worked hard to restore access to our apps and services and are pleased to announce that they are now operational." We appreciate your understanding."
The cause of the issue was not disclosed by Facebook.
When Facebook's websites and apps responded with server errors shortly before noon ET, all three platforms went down. According to reports on DownDetector.com, the outages were widespread, but it was not clear how many users were affected.
The outage was caused by a DNS issue, according to ThousandEyes, a network monitoring service owned by Cisco. It functions as a website directory.
It was Facebook's longest outage since 2008, when a bug knocked it offline for about a day, affecting approximately 80 million users. Facebook now has 3 billion users.
Facebook's chief technology officer, Mike Schroepfer, apologized in a Twitter post.
"Sincere apologies to everyone who is currently affected by outages of Facebook-powered services," Schroepfer wrote. "We are experiencing network issues, and our teams are working as quickly as they can to identify the problem and resolve it as soon as possible."
The same outage took about an hour in 2019. This outage was caused by an update to the server configuration, according to Facebook.
The controversy arises just one day after a whistleblower who leaked confidential data to The Wall Street Journal and Congress revealed her identity before appearing on "60 Minutes."
The documents, which were first revealed in a series of Journal stories, revealed that Facebook's top executives were aware of Instagram's negative effects on younger users and that Facebook's algorithm enabled the spread of fake news and other misinformation.