How useful are the courses available on Udemy and Coursera?

udemy The Best Alternatives to Udemy · 1 Educative · 2 SkillShare · 3 Udacity · 4 edX · 5 FutureLearn · 6 LinkedIn Learning · 7 Codecademy · 8 Khan Academy

Udemy Courses · Geology: Earth Science for Everyone · Web Design for Web Developers: Build Beautiful Websites! · Software Testing Simple (Software Quality udemy Udemy has more than 35 million users learning new skills from 57,000 expert instructors who've produced over 130,000 online courses Tutorials