Duolingo Test Center, Africa, IELTS, and CEFR

When we launched Duolingo Test Center, our goal was to make language certification as secure, accessible, and affordable as possible. Now, about one year later, more than 90,000 people have taken the Duolingo Certificate exam in English, which is already being used by global organizations like Upwork and Crowdsite, and accepted by forward-thinking academic programs at Harvard, the Max Planck Institute, and others.

A Case Study in East Africa

We were excited to learn that Carnegie Mellon University in Kigali, Rwanda has been using Duolingo Certificates as part of the admissions process. Even though they still officially required TOEFL or IELTS scores from their 2015 applicants, East Africa is a region where those tests can literally cost four months' income for the average person (not to mention travel costs and limited test center availability)1. CMU's admissions team used the more accessible Duolingo Test Center at the beginning of the application process, and then required only the most likely candidates to spend their hard-earned money on more expensive assessments. This process created a really interesting data set...

More Evidence for Validity

Associate Director Michel Bézy contacted us in July with a not-so-surprising result: Duolingo Certificate scores are significantly correlated with IELTS scores (r = 0.834) that were submitted by their applicants (97% of them submitted IELTS scores). I worked with Dr. Bézy to further analyze the data, linking Duolingo scores to IELTS scores and CEFR levels, which were consistent both with (1) previous independent research linking Duolingo scores to TOEFL, and (2) the way Duolingo's scoring scale was originally designed.

Read our full research report to learn more!

Accessible Language Learning (and Assessment) for the World

Education is the key to socioeconomic mobility, and Duolingo is proud to provide more than 100 million people the opportunity to learn a language for free. Encouraging results like this for Duolingo Test Center show it is also possible to make precise language certification available at a fraction of the price of established alternatives. We're excited about the road ahead for the Test Center and language learners around the world...


  1. IELTS and TOEFL administrations in Kigali, Rwanda cost $200 and $250 respectively. According to the International Monetary Fund, 2014 per capita income in Rwanda was just $741.