FutureLearn 3 hours a week , 3 weeks long 3 hours a week , 3 weeks long

Coursera 33 hours worth of material , 3 weeks long 33 hours worth of material , 3 weeks long

edX 6-18 hours a week , 12 weeks long 6-18 hours a week , 12 weeks long

Coursera 17 hours worth of material , 4 weeks long 17 hours worth of material , 4 weeks long

Complexity Explorer 2-4 hours a week , 7 weeks long 2-4 hours a week , 7 weeks long

edX 2-3 hours a week , 12 weeks long 2-3 hours a week , 12 weeks long

Coursera 11 hours worth of material , 5 weeks long 11 hours worth of material , 5 weeks long

Coursera 25 hours worth of material , 11 weeks long 25 hours worth of material , 11 weeks long

Coursera 22 hours worth of material , 8 weeks long 22 hours worth of material , 8 weeks long

Udacity 8 weeks long 8 weeks long

Coursera 15 hours worth of material , 6 weeks long 15 hours worth of material , 6 weeks long

Coursera 30 hours worth of material , 14 weeks long 30 hours worth of material , 14 weeks long

Coursera 15 hours worth of material , 6 weeks long 15 hours worth of material , 6 weeks long

Coursera 12 hours worth of material , 4 weeks long 12 hours worth of material , 4 weeks long

edX 5-10 hours a week , 10 weeks long 5-10 hours a week , 10 weeks long

Udacity 3 weeks long 3 weeks long

Complexity Explorer 9 weeks long 9 weeks long