Stanford Online offers free courses in AI, ML, NLP, and entrepreneurship taught by Stanford faculty.
AWS Cloud Practitioner Essentials — free 6-hour foundational AWS course preparing for the CCP certification exam.
Khan Academy provides completely free comprehensive courses in math, science, economics, and test prep.
HubSpot Academy offers free marketing, sales, and service certifications used widely in the industry.
Udemy offers thousands of free courses — find them in the dedicated free section with lifetime access.