The company, which has over 1,100 employees and is based in San Francisco, had been expected to pursue an initial public offering. But after the rocky I.P.O. of Uber and the failure of WeWork’s planned offering, some companies have instead pursued the surer path of a sale rather than face potentially skeptical investors.

Last month, another successful fintech start-up, Plaid, sold itself to Visa for $5.3 billion rather than stage an I.P.O. Plaid’s business is also focused on consumer data, serving as the middlemen between the big financial firms that have that data and the start-ups that need it.

The deal negotiations were earlier reported by The Wall Street Journal.

Credit Karma was started in 2007 by Kenneth Lin, the current chief executive, and two co-founders, after Mr. Lin had trouble acquiring his own credit score. Until about a decade ago, consumers generally had to buy a credit score directly from the three major credit bureaus. Otherwise, the most likely opportunity for individuals to get a sense of their creditworthiness came just as they were applying for a loan — when it was too late to do anything to improve their lot.

Signing up for the site became a rite of passage for Americans looking to get their credit score in shape to apply for a mortgage. In addition to providing credit scores from TransUnion and Equifax, Credit Karma offers advice on how the scores could be improved by doing things like lowering credit card balances.

The company made its money by offering its customers new credit cards and online loans, based on their credit scores. When customers accepted the offers, Credit Karma would receive payments of a few hundred dollars, though it closely guarded the details of these deals.