All Subjects: Online Course Guides by Topic (2026)

START HERE

Every subject we cover, with the guide to start from and the specific breakdowns underneath it. Pick the thing you want to be able to do — we will tell you which course is worth paying for, and which is not.

Maintained by Josh Hutcheson, editor of OnlineCourseing. See our review methodology.

We buy the courses, take them, and report back. Nothing here is pay-for-placement, and every pick is one we would spend our own money on. Start with a subject guide, then drill into the specific comparison or pricing breakdown you need.

Languages

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Apps, live tutors and structured courses, ranked by how fast they get you speaking.

Start with the languages guide →

Finance & FMVA

Financial modelling, valuation and the credentials finance employers actually ask for.

Start with the finance and fmva guide →

Data Science

Analysis, engineering and the tooling that data teams hire for.

Start with the data science guide →

AI & ML

Machine learning, deep learning and the new wave of applied-AI credentials.

Start with the ai and ml guide →

IT & Cybersecurity

Cloud, networking, security and the certification ladders that lead to IT jobs.

Start with the it and cybersecurity guide →

Coding & Dev

Languages, frameworks and bootcamps, judged on whether you finish employable.

Start with the coding and dev guide →

Marketing

SEO, paid media, content and sales — the skills that move revenue.

Start with the marketing guide →

Design & UX

Product design, graphics, photography and video, from beginner to portfolio.

Start with the design and ux guide →

Business

Management, operations and the general-business skills that get people promoted.

Start with the business guide →

Test Prep

Exam routes and prep providers, compared on pass rates and price.

Start with the test prep guide →

Still deciding?

If you are weighing two specific options, we have an index of every head-to-head comparison. If the question is cost, see our platform pricing breakdowns, or start from our ranking of the best online learning platforms.