SAN FRANCISCO — Slack, the workplace messaging startup, disclosed the details of its business in an offering prospectus Friday as it joined the parade of tech companies that plan to publicly list their shares this year.

Sharing its financial results widely for the first time, Slack said that it collected $400.6 million in revenue in its latest fiscal year, which ended Jan. 31. That was nearly double what it generated in the previous fiscal year. It lost $140.7 million in the latest fiscal year, narrowing its losses from $180.9 million the year before.

The company had 88,000 paying customers at the end of the most recent fiscal year, up almost 50% compared with the previous year. Of those customers, 575 paid more than $100,000 for their subscriptions, contributing about 40% of the company’s revenue.

Friday’s filing sheds more light on Slack, which has grown out of a video-game company into an increasingly common way for workers to communicate. Its software is meant to be a replacement for email — but it also lets colleagues chat, share files and more.

Slack’s filing followed the initial public offerings of two other high-profile startups, Lyft and Pinterest. The biggest tech public offering of recent years — that of the ride-hailing giant Uber — is also on deck, with Uber pricing its shares Friday in a stock sale that is expected to value it at as much as $91 billion.

The IPO boom has had mixed results. Lyft’s shares sank below their IPO price after an initial spike last month. Pinterest’s stock has stayed above its offering price since its debut on the market this month.

But less-prominent startups that sell software to other businesses have performed better. Shares of Zoom, a video conferencing company, rose 80% on its first day of trading as a public company this month, and PagerDuty, which sells software to help companies respond to complaints and other incidents, experienced a first-day pop of 60%.

Unlike most other Silicon Valley darlings going public this year, Slack is not holding an initial public offering, where it sells shares to the public. Instead it will carry out a “direct listing,” where it simply lets its shares start trading on a stock market. It plans to do on the New York Stock Exchange, under the ticker symbol “SK.”