Facebook suffered a widespread outage that left the social media site inaccessible to many users worldwide on January 27.
The outage lasted about 40 minutes and affected users in the United States, Asia, Britain, and Australia.
Access in some other locations appeared to be spotty as well.
The social media giant's Instagram service was also inaccessible for a period.
Facebook has about 1.25 billion users and Instagram has about 300 million.