Facebook users spent less time on the site even before it announced major changes to its News Feed in January, BBC reports.
Measures such as showing fewer viral videos cut time spent on the social network by about 5%, or roughly 50 million hours a day, in the last three months of 2017.
Chief executive Mark Zuckerberg said the priority was encouraging more personal interaction among users.
"Helping people connect is more important than maximising the time they spend on Facebook," he said.