The company plans to sell 36 million shares of Class A stock at between $16 and $18, bringing in as much as $648 million, according to the filing with the Securities and Exchange Commission.
As a result, the IPO will be among the largest tech market debuts since Snap in March of 2017.
Dropbox also plans a $100 million sale of stock to the venture capital arm of Salesforce, according to the filing.
According to a Bloomberg calculation, the transaction would value Dropbox at $7.1 billion, less than its $10 billion value during a prior private capital raising effort in 2014.
The company first confidentially filed for an IPO at the start of the year.
The company is currently losing money. While it claims to have 500 million users in 180 countries, it posted only 11 million paying clients at the end of last year.