Duolingo crowned as “undisputed champion of tracking”

While you learn a language, your language app is learning about you. Not exactly breaking news, is it?

Many of us have made peace with the fact that a treasure trove of our personal information is circling the web. Maybe I’m among the 2.6 million Duolingo users whose data has been recently exposed. It might not matter much since most of that information, including my phone number, has already been leaked before. Thanks, Facebook and Co.

Following the Duolingo leak, cybersecurity company Surfshark went on digging into the most data-hungry language learning apps. Researchers listed 32 potential data points that language apps are, or might be, collecting. Duolingo, with over 500 million registered users and over 60 million monthly active users, collects 19 data points, including names, email addresses, and phone numbers.

However, researchers don’t seem to be concerned about the volume of data collected but in how it’s being managed.

“Many of these apps use collected data to track users, which is often done by sharing user data with third-party advertisers or even data brokers. Nine out of ten analyzed apps employ collected data for tracking purposes, with an average of three data points handled in this manner,” they noted.

Duolingo apparently used two-thirds of collected data, including purchase history, coarse location, and phone number, for tracking.

“Duolingo takes the lead in this category as well, emerging as the undisputed champion of tracking. It uses two-thirds of collected user data (13 out of 19 data points) for tracking purposes, which is four times the average among the analyzed apps,” Surfshark researchers said.

The second most data-hungry app on the Surfshark’s list is Busuu, with over 100,000 registered users and 10,000 “live teachers” for one-on-one tutoring.

“On the opposite end of the spectrum, some apps adopt a more privacy-oriented approach. For example, EWA collects five out of 32 data points, HelloTalk gathers seven, and Mondly captures eight. Despite its conservative data collection, HelloTalk, surprisingly, tracks users' precise locations – a feature not found in any of the other analyzed apps,” researchers said.

The previous version of this article claimed that the app sells data to third parties. However, according to the app, this is not true. It assured Cybernews that it "does not sell any data to third parties." We have sent the company additional questions to understand why it collects so much data, and here's what it told us.

“All the data Duolingo collects is publicly declared in the "App Privacy" section of their App Store listing here. Duolingo collects data mainly to improve the performance of their products and how well they teach. Some of the data is also used to personalize the advertising that free learners see.”