TikTok US users were using a Chinese social app called RedNote before the TikTok ban, and the number of people learning Chinese on Duolingo is growing. The U.S. law is scheduled to take effect on January 19. Unless stopped by the Supreme Court, TikTok will be removed from the U.S. app store and prevent the app from running on user devices unless the user installs a VPN client.

However, rather than trying to get around the ban, more than 700 million TikTok users have turned to the social video platform RedNote (aka Little Red Book), fostering a surprising — not to mention considerable — cultural exchange between citizens of the two countries. Many American users have been asked to help Chinese users with their English homework.

While some TikTok refugees encountered technical issues signing up for RedNote, while others were summarily kicked out for community violations, the intention of switching from one Chinese app to another is to send a strong signal to the U.S. government, Meta Potential TikTok competitors such as TikTok argue that there is demand for the type of social networking experience that China creates and that American companies can only try to imitate.

The move is also a test of whether U.S. users are worried about Chinese companies collecting their personal data for nefarious purposes — one of the key factors that led to TikTok being banned in the first place. (Turns out, as this migration shows, many are neither.)

However, since Shanghai's Little Red Book/Red Notes is designed for a Chinese audience, the default language of the app is Mandarin. That's prompted an increase in U.S. users of the Duolingo language-learning app taking crash courses in Mandarin.

According to Duolingo, the app's new Mandarin learning volume in the U.S. is up about 216% compared to the same time last year, with RedNote adoption rising sharply in mid-January. Additionally, the company reported a corresponding spike in the number of people who selected "TikTok" as a response to a "How did you hear about us" survey that prompts new users to respond.

"Oh, now you're learning Mandarin," the company joked in an X post on Tuesday. It also posted a video on TikTok promoting the use of its app to learn Chinese. The short video shows the company's green owl mascot at an airport heading to China, overlaid with text that reads "Me, because I'd rather move to China and learn Mandarin on Duolingo." The video has now garnered over 500,000 likes. Another recent video focused on teaching Mandarin phrases to “TikTok refugees” received more than 620,000 likes.

Consumer demand for Duolingo's language learning courses has also impacted the app's install base, according to app intelligence provider Appfigures.

The company reported a 36% increase in downloads of Duolingo's app on the U.S. App Store and Google Play as of January 3, an early sign that users may be jumping on the RedNote bandwagon later this month. Tried different Chinese social apps.

A week ago, Duolingo was ranked around 40 in terms of top apps (excluding games) and overall ranking (including games). As of now, it ranks 22nd in the overall ranking and 20th in the top apps ranking.