https://www.coursera.org/
https://www.khanacademy.org/
https://www.edx.org/
https://www.codecademy.com/
https://www.udemy.com/
https://academicearth.org/
https://ocw.mit.edu/
https://alison.com/
https://www.skillshare.com/ (共享互動)
https://www.classcentral.com/ (常春藤盟校)

Google Career Certificates https://grow.google/certificates/

http://www.openculture.com/freeonlinecourses
https://www.ted.com/talks

http://www.apu.edu/
http://www.phoenix.edu/

語言：
https://www.memrise.com/

小孩：
https://kids.nationalgeographic.com/

台灣：
https://hahow.in/