Average monthly active users (MAUs)—a key measure of growth for Twitter—came in at 304 million for the quarter, 12 percent higher than a year earlier but only up slightly from 302 million in the previous quarter. About 80 percent of the company's MAUs came from mobile.
The metric—which did not include users who sign up for the platform through text message—fell short of expectations from analysts, who projected 310 million MAUs, according to StreetAccount. Noto added that the company plans to ramp up marketing efforts to stress the platform's value and reach the mass market.
"Our Q2 results show good progress in monetization, but we are not satisfied with our growth in audience," said Jack Dorsey, Twitter's co-founder and interim CEO, in a statement. "In order to realize Twitter's full potential, we must improve in three key areas: ensure more disciplined execution, simplify our service to deliver Twitter's value faster and better communicate that value."
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Dorsey—who took over the post at the start of the month after Dick Costolo stepped down—has said repeatedly that he does not intend to change Twitter's strategy. The company has searched for a new full-time head and Dorsey added in the conference call that it would provide an update when it had "meaningful" news.
"I think that Twitter has an awesome product and Periscope has so much potential but they need management," said Ross Gerber of Gerber Kawasaki, which owns Twitter stock, in a CNBC "Closing Bell" interview Tuesday.
Twitter's advertising revenue rose 63 percent year over year to $452 million, ahead of estimates for about $426 million, according to StreetAccount. Mobile ad sales—a crucial and crowded space—made up 88 percent of that total.
"It's a pretty good story from a company that folks had really dumped on here and had had a tough time of it in almost any metric," said Max Wolff of Manhattan Venture Partners in a "Closing Bell" interview Tuesday. "That being said, it's not enough to turn the story from kind of bad to wonderful, it's just enough to stabilize."
Promoted tweets and videos within those posts helped drive growth, Noto said. He added that engagements with ads grew 53 percent year over year.
The company cut its guidance on full-year capital expenditures to a range of $450 million to $550 million. It was previously set at $500 million to $650 million, according to StreetAccount.
Twitter's projected revenue of $545 million to $560 million in the third quarter fell in line with analysts' expectations of about $556 million. It raised its full-year sales guidance slightly to $2.20 billion to $2.27 billion.
—CNBC's Everett Rosenfeld contributed to this report.