When you buy through our links, Insider may earn an affiliate commission. Learn more.

• Some of the best schools in the world offer free online courses on edX, Coursera, and FutureLearn.
• Below, you can find the most popular online course from each university, based on enrollment.
• Schools include Harvard, MIT, Stanford, Princeton, Yale, UC Berkeley, Columbia, etc.

Whether you fancy attending a conference at Yale or sampling a University of Michigan course before applying to graduate school, online learning offers a convenient way to explore your interests or acquire new valuable skills.

On online learning platforms like edX, Coursera, and FutureLearn, you can take thousands of online courses run by accredited universities, many of which are completely free. Most also offer optional paid certificates of completion that you can add to your resume or LinkedIn, or are part of longer programs that can potentially be more affordable alternatives to on-campus learning.

To narrow down all the free options, we’ve featured the most popular free online courses from top 20 universities, as ranked by US News. (Note: The University of California Los Angeles and University of California San Francisco do not offer online courses through these platforms, so they do not appear on this list.)

We determined popularity by the highest number of current registrations and have included courses that are part of longer certificate programs (because you can still audit them for free).

The Most Popular Online Course Among Top 20 Colleges: