Stitch Fix, the fast-growing online fashion retailer and personal styling service, has filed confidentially to go public, according to a person familiar with the filing. The company could be looking for a valuation of $3 billion to $4 billion in the offering, Reuters reported earlier this year. TechCrunch first reported the news of the confidential filing on Friday, following a Recode report from earlier this week that said the company could submit the paperwork within days. The five-year-old company, founded by CEO Katrina Lake, sends boxes of clothing and accessories to customers personalized to their tastes. Stitch Fix says it uses a combination of algorithms and stylists to choose what it sends to each customer. Customers pay an initial $20 styling fee that can be used toward the purchase of clothing they keep, and receive a 25 percent discount if they purchase every item. Confidential filings like this one were introduced in the 2012 JOBS Act. They were designed to allow “emerging growth” companies to file a draft S-1 with the SEC in order to get initial feedback from the commission without the public scrutiny of investors, competitors and the media that comes with a public filing. Read more at Recode.