> Free Courses

> cs50.harvard.edu ↗

Harvard's actual intro-to-computer-science course, the real one, free.

fully free

> freecodecamp.org ↗

Full curriculum from web basics through backend/data science, with real certifications.

fully free

> khanacademy.org ↗

K-12 through early-college math, science, economics - the original free-education-for-everyone platform.

fully free

> ocw.mit.edu (MIT OpenCourseWare) ↗

Actual MIT course materials - lecture notes, problem sets, some full video lectures.

fully free

> exercism.org ↗

Hands-on coding exercises with real human mentor feedback, across 70+ languages.

fully free

> w3schools.com ↗

Reference-style web dev tutorials (HTML/CSS/JS/SQL etc), try-it-yourself editor built in.

fully free

> programiz.com ↗

Beginner-friendly programming tutorials with an in-browser compiler.

fully free

> duolingo.com ↗

Language learning, gamified, ad-supported free tier is fully functional.

fully free (ad-supported), paid tier removes ads/adds features

> ted.com ↗

Not a structured course, but a huge free library of expert talks across every field.

fully free

> leetcode.com ↗

Data structures & algorithms practice problems, the standard interview-prep grind.

free tier covers most problems, premium adds company-specific question sets

> coursera.org ↗

University-partnered courses - audit any course's actual video lectures and readings for free.

free to audit, paid for a certificate/graded assignments

> edx.org ↗

Same model as Coursera - university courses (MIT, Harvard, etc), audit track is free.

free to audit, paid for verified certificate

> alison.com ↗

6,000+ courses across trades, business, and tech, with genuinely free certificates - not just free audit.

fully free including basic certificate, paid tier removes ads and adds premium diplomas

> skillshare.com ↗

Creative-skills classes (design, illustration, video, business).

paid subscription required beyond a trial - listed for completeness, not a "free" pick