汇总一下提供免费证书的在线课程。
Class Central
https://www.classcentral.com/report/free-certificates/
Alison
https://alison.com/certificate-courses
Simplilearn
https://www.simplilearn.com/skillup-free-online-courses
Free-courses-with-Certificates
https://github.com/avinash201199/Free-courses-with-Certificates
Free Certifications
https://github.com/cloudcommunity/Free-Certifications
https://free-certifications.com/
许久不更新了，但一些内容还依然有效