Learning How to Learn: Powerful Mental Tools to Help You Master Tough Subjects – a popular online course that can be audited for free.
edX – a comprehensive selection of FREE online courses from Harvard, MIT, and more. In some cases students can pay for completion certificates and credentials.
Coursera – Online courses from universities around the world. Much of Coursera’s content is free—though you can also upgrade to a paid plan to receive official course completion certificates or even enroll in online degree programs.
Class Central – if you’re not sure where to start or even what you want to learn about, browse Class Central, which aggregates courses from several of the platforms listed here. You can search by subject or school to see the options available across Coursera, edX and more. See their categorized list of 450 free online Ivy League university courses.