The company's shares were up 1.4 percent at US$168 after the bell. Through Wednesday's close, the stock had climbed nearly 44 percent this year.
Facebook said about 2.01 billion people were using its service monthly as of June 30, up 17 percent from a year earlier.
The social media giant said in June it had surpassed the 2-billion user mark.
Mobile ad revenue accounted for 87 percent of the company's total advertising revenue of US$9.16 billion in the latest quarter, up from 84 percent a year earlier.
Analysts on average had expected total ad revenue of US$9.02 billion, according to data and analytics firm FactSet.
Facebook is expected to generate US$36.29 billion in net digital ad revenue this year, a 35 percent jump from 2016, according to research firm eMarketer.
Net income attributable to Facebook shareholders rose to US$3.89 billion, or US$1.32 per share, in the second quarter ended June 30 from US$2.28 billion, or 78 cents per share, a year earlier.
Total revenue rose 44.8 percent to US$9.32 billion.
Analysts on average had expected earnings of US$1.13 per share and revenue of US$9.20 billion, according to Thomson Reuters I/B/E/S.
In the first quarter, Facebook changed the method it reports earnings, focusing on Generally Accepted Accounting Principles (GAAP) earnings instead of non-GAAP.
Reporting by Rishika Sadam. Editing by Sriraj Kalluvila