Investors in Fitbit include Qualcomm Ventures and SoftBank Capital, according to the company's official website.
The number of shares and price haven't been disclosed yet. Fitbit gave no specific plan for the proceeds from the IPO.
Fitbit sold 10.9 million devices last year, according to its filing, and another 3.9 million in the first quarter of this year. The company had reported revenue of $336.8 million and net income of $48 million for the three months ended in March 31.
Fitbit specializes in the production of tracking devices that monitor health and fitness. The device records calories burned and the activity level of users, among other metrics. The company now faces an Olympic-level competitor, as the new Apple Watch offers a whole spread of health and fitness services.