Inside the indeterminate walls of the Internet, a plethora of useful services and learning tools await. With the infinite resources the web provides, it's not terribly difficult to find websites that will teach you new and interesting skills. What is hard, however, is finding free sites that can educate you, without forcing you to fork over your hard earned bitcoins—or at least a few incriminating selfies—to gain some sterling nuggets of knowledge.
These 31 outlets of digital know-how will enlighten you, excite you, and if you stick around long enough, you may just learn a life-changing lesson in the process. College is overrated. Consider this list your debt-free alternative.