Facebook said daily active users climbed 18%, to 1.23 billion, in December 2016, versus the year-ago period.
Average mobile DAUs rose 23%, to 1.15 billion, in December, while monthly mobile MAUs reached 1.74 billion, up 21% from a year earlier.
Overall monthly active users jumped 17% to 1.86 billion in Dec. 2016 versus the year-ago period.
Facebook posted total Q4 revenues of $8.8 billion, up 51% from $5.84 billion in the year-ago period. The bulk of it came from ad revenue of $8.62 billion, up 53% from $5.63 billion. $4.55 billion of total revenues came from the U.S. and Canada, $2.06 billion from Europe, $1.34 billion from Asia Pacific, and $839 million from the rest of the world.
Mobile ad revenues represented about 84% of all ad revenue in Q4, versus 80% a year earlier.
Facebook notched GAAP net income of $3.56 billion ($1.21 per share), up 128% from $1.56 billion (54 cents).
Results handily beat Wall Street estimates. Facebook shares were up 2.2% in early after-hours trading Wednesday.
Facebook ended 2016 with cash and cash equivalents and marketable securities of $29.45 billion.