[2022] The 250 Most Popular Online Courses of All Time

The best way to choose a free Massive Open Online Course (MOOC) is to choose one that other people have taken and enjoyed.

Class Central has been maintaining a catalog of these MOOCs ever since they rose to popularity back in 2012. According to Class Central’s 2021 annual report on MOOCs, 220M students have taken at least one course and over 950+ universities have launched 19,400+ courses.

To help learners decide which course to take, Class Central publishes a number of different rankings for best online trainings, including the Best Online Courses of all time based on the tens of thousands of reviews written by Class Central users.

In this ranking, we take a different approach. Instead of ranking courses by reviews, we rank by the number of students who enrolled in the course. In some cases, the best online classes based on reviews are also the courses with the most enrollments. In other cases, courses with large enrollments only have average reviews. This suggests there are popular courses that Class Central’s reviews have missed.

If you are looking for free certificates, check out some of our compilations:

Most Popular Online Courses of All Time

Here’s a quick summary of 250 most popular free online courses of all time, based on the number of enrollments:

  • Enrollments range from 160K to 4.5 million. There are 15 courses with over 1 million enrollments.
  • Together, they account for over 104 million enrollments, with an average of 416K enrollments.
  • Interestingly, almost 40% of the courses are in the field of Business and Humanities.
  • Over 76K reviews have been written on Class Central with an average rating of 4.02.
  • 227 courses are in English, 19 are in Spanish and rest of them are in French, Dutch, and Portuguese.
  • All courses are free to audit. You may need to pay for a certificate.
  • Combined, they represent thousands of hours of content.

Interest in MOOCs and online education has never been greater. If you’re looking for a new online course, take a look at these free courses that millions of students have already taken. Here are the 250 most popular online courses, sorted by number of enrollments:

In addition to this, Class Central also publishes the 100 Most Popular Courses of all time for each year. For these rankings, we only look at courses launched in that year.