Four kinds of provider, and what free means at each
Every provider in the index is one of four kinds: a university, a course platform, a company or a non-profit. The kind predicts what you get without paying. Universities give away teaching and, with few exceptions, charge for credentials; platforms give away access under conditions set by the platform; companies give away training in their own products, usually with a free certificate; non-profits give away everything they have.
Universities offering free online courses
Harvard (40) ties with MIT for the most listed university courses, and the CS50 family is the only set of full university courses here with a free certificate: it is published as OpenCourseWare, and anyone scoring at least 70% on the graded work is eligible for a free verifiable certificate, while HarvardX courses on edX are free to audit with a paid certificate at $69 to $299. MIT (40) publishes OpenCourseWare with no account, no deadline and no certificate, plus MITx courses with a free audit track and a paid certificate. Stanford (18) has complete Engineering Everywhere courses under a Creative Commons licence, StanfordOnline courses on edX, and short medical-education activities whose registration fee is waived and whose certificate comes through Stanford's CME portal.
Yale (17) and Princeton (14) are the clearest cases of teaching without credentials: Open Yale Courses are full semester lecture courses with no registration and no certificate, and Princeton states that none of its open courses on Coursera or edX offers any credential at all. UC Berkeley (9) is listed only through edX; its BerkeleyX courses are free to audit for the course's estimated length from the day you enrol, with a verified certificate at $130 to $200. Oxford (9) lists open-licensed lecture recordings with transcripts, with no assessment or certificate, alongside OxfordX courses on edX whose certificate costs $189 to $249.
Free online learning platforms
edX (64) is the largest source in the index once the university courses hosted there are counted. Free means the audit track: readings, lectures and ungraded exercises, no graded work, no certificate, and access that expires after the course's estimated length. Coursera (29) announced in August 2025 that a first-module preview replaced its audit experience, so we list only the courses whose page still offers the full course without a certificate. Alison (24) lets you study every course in full, including assessments, and sells the certificate afterwards, with a short legacy list of courses whose digital certificate is free.
Companies that train you in their own products
Google (12) is listed mainly through Skillshop, where the courses and certifications are free and a certification is valid for one year; one Applied Digital Skills lesson from Google for Education is listed too. IBM (13) is listed through Cognitive Class, whose courses end in a graded final exam and a free certificate of completion, plus one IBM SkillsBuild course with a free Credly badge. Microsoft (11) is listed through Microsoft Learn, where learning paths are free to read but end in a trophy, not a certificate; Microsoft's certification exams are paid and are not listed.
Non-profits that charge for nothing
Khan Academy (10) is donor-funded and puts no lesson behind a paid tier (its Khanmigo tutor is a separate, optional subscription), but it issues no certificates and is not an accredited school, so its courses appear on subject pages and never on the certification pages. freeCodeCamp (14) is also a charity, and its certification exams and certificates are free; each certificate is published at a public URL showing the holder's name and completion date.
Which providers give a free certificate
If the credential is the point, the provider settles the question before any course page does.
- Free certificate on every listed course: Google, IBM, freeCodeCamp and HubSpot Academy.
- Free certificate on some courses: Harvard (the CS50 family), Stanford (medical-education activities), Alison (a single course from the legacy list) and AWS (badge paths and Cloud Quest roles).
- Paid certificate only: edX's own catalogue on edX, UC Berkeley, Oxford, Cornell, MITx courses at MIT, and the Coursera courses that offer one.
- No certificate at all: Khan Academy, Princeton, Microsoft Learn, Udemy's free courses, MIT OpenCourseWare, Open Yale Courses and Oxford's podcasts.
- The free certification courses hub collects every course whose certificate is free, across all providers.
Providers with courses but no page yet
Not every provider has a page of its own yet, but their verified courses already appear on subject and certification pages. HubSpot Academy (13) offers free certification courses with an exam and a shareable badge, and its courses are gathered on the HubSpot certifications page. AWS (9) is listed through the free tier of Skill Builder, where knowledge badges are free to earn and claim through Credly; see AWS certifications. Udemy (16) courses are free when the instructor sets no price, but Udemy's own policy is that free courses carry no certificate of completion, so they never appear on certification pages. Cornell (2) has only its CornellX courses on edX, free to audit with a paid certificate, because eCornell sells its programmes and we found no free course in its catalogue; too few to justify a page until more are published.
How to use a provider page
Each provider page opens with a fuller explanation of what free means there, followed by a ranked table of its verified courses that you can filter by cost, certificate, level and subject. Platform pages such as edX and Coursera also list the university courses hosted there, so a HarvardX course appears on both the Harvard and the edX page. If you would rather choose by topic than by institution, start from the subjects page instead, or from the free online courses with certificates page when the credential matters.