Crash Course is a popular US based youtube channel with over 10 Million subscribers The short Educational Videos provide comprehensive overviews of specific subjects, divided into categories including World History, Engineering, Statistics, History of Science. Particularly useful for older students.

A rich library of resources provided by the Smithsonian museum alongside crowdsourced resources, covering a huge range of topics, ranging from elementary arithmetic to the depiction of women in art. The homepage provides guides to how the resources are organise, as well as suggestions (based on the US grade education system) as to where to look.