Harvard University is offering 70 of its online classes for free (liberal arts, science, computer science). Though you won’t earn credits or receive a diploma/certificate, you can use your time to: prepare for a future class, investigate an area of interest, and stay focused on your education. Of particular note in Harvard’s online offerings: their high production values and effective use of videos with the professor and text/image overlays.
For more information, visit:
https://online-learning.harvard.edu/catalog/free