Advertising revenue has also been rising, but by less than was forecast.
Some observers have questioned Mr Musk's commercial judgement in buying Twitter, a platform that despite its high profile has not consistently made high returns.
In the latest quarter it made a profit of $513m (£412m) on revenues of $1.2bn.
Daily active users of the platform rose to 229 million, up from 199 million a year earlier, the company said, publishing its latest financial results.
New users grew faster outside the US, by 18.1%, than in its home market where numbers were up 6.4% over the 12 months to the end of March.
This week Twitter's board agreed a $44bn sale to Tesla boss, Mr Musk, the world's richest person, and a prolific user of the platform.
In publishing its results, the firm said it was withdrawing all previously provided guidance over its immediate commercial outlook.
However, it did say revenues had been affected by "headwinds associated with the war in Ukraine".
Mr Musk's purchase is likely to take several months to complete, after which the company will be owned privately.
While Mr Musk has not made clear his precise plans for the platform, he has spoken about reducing advertising, and cracking down on "bot" or automated accounts. He has also prompted controversy by suggesting there may be a new approach to how Twitter moderates free speech.