“The number of shares to be offered and the price range for the proposed offering have not yet been determined,” it said in the post. “The initial public offering is expected to occur after the SEC completes its review process, subject to market and other conditions.”

As of August, Reddit said it had a valuation of about $10 billion after raising more than $400 million from Fidelity Investments Inc. In February, the social-media company said it had raised about $500 million at a $6.5 billion valuation.

Reddit has been looking to build on the attention it gained when at the start of the year its WallStreetBets forum became a hot spot for the individual investors who rallied around

GameStop Corp.

and other stocks.

The episode brought in millions of new users, Reddit CEO

Steve Huffman

said in its wake, as well as new advertisers, the source of the bulk of the company’s revenue. He has also said that with an IPO, he would want to make Reddit’s share offering more accessible to individual investors.

San Francisco-based Reddit, founded in 2005, is known for its message boards on an array of topics, plus its “ask me anything” digital town halls with celebrities, politicians and subject-matter experts. The company was sold to Condé Nast in 2006, and the magazine publisher’s parent, Advance Publications Inc., spun Reddit off in 2011 and remains a shareholder.

Over time Reddit has grown to outpace rivals such as Digg to become a haven for niche communities to gather and a go-to source of news. Reddit had more than 50 million daily users as of January, according to its website. In August the company said it reached $100 million in advertising revenue in a quarter for the first time, almost triple the prior-year figure, but that it remained unprofitable.

Reddit’s market debut will come after a year for IPOs like no other. More than 900 companies have gone public in 2021, raising nearly $300 billion in 2021, including electric vehicle maker Rivian Automotive Inc., dating app

Bumble Inc.

and mobile-videogame maker

Playtika Holding Corp.

Along with Fidelity, Reddit’s investors include venture-capital firms Andreessen Horowitz and Sequoia Capital, and Chinese technology conglomerate

Tencent Holdings Ltd.

In recent years, Reddit has been taking steps to grow by investing in areas such as video and consumer products, as well as by moving into international markets. But like many other social-media companies, it’s also been plagued with content-moderation challenges, including how to stop the spread of misinformation and calls for violence.

In 2020, Reddit banned “The_Donald,” a community devoted to former President

Donald Trump,

saying moderators frequently ignored content that violated its platform’s rules.

Thanks to the GameStop trading frenzy, Reddit has become a hot spot this year for everyday Wall Street investors seeking advice. At The Wall Street Journal’s Tech Live conference in October, Mr. Huffman said he was hoping a lot of individual investors would participate in Reddit’s initial offering.

“Retail investors are usually the last and probably at the worst price” for initial offerings, Mr. Huffman said at the event. “But the way the market is evolving to be more fair I think is really exciting.”

Write to Sarah E. Needleman at sarah.needleman@wsj.com