The short-messaging service said profit rose to $1.1 billion, lifted by a one-time tax benefit, up from $100 million a year earlier. Excluding special items, profit was $37 million.

Revenue was better than expected at $841 million, up 18 percent from a year ago. The vast majority of revenues came from advertising.

Twitter's new measure of its user base -- monetizable daily active users -- was 139 million, compared to 122 million in the same period last year.

Shares in Twitter rallied 6.9 percent in pre-market trades following the release.

"Twitter's value proposition to advertisers is not the size of its audience, but the engagement of its users," said eMarketer analyst Jasmine Enberg.

"The strong growth in monetizable daily active users shows that Twitter users are sticking with the platform, and that should resonate with advertisers."

The results showed Twitter remains profitable and is boosting the number of users even as it moves aggressively to weed out fake accounts and curb abusive content.

"Health remains our top priority and we are proud of the work we did in Q2," chief executive Jack Dorsey said in a statement.

"Our focus was on ensuring that our rules, and how we enforce them, are easy to understand. We also continued our work to proactively identify and address malicious behavior, resulting in an 18 percent drop in reports of spammy or suspicious behavior."