JavaScript: The Hard Parts, v2 vs Codecademy Learn JavaScript

Goes deep on the JavaScript runtime model — thread of execution, the call stack, closure, the event loop, Promises and prototypes/classes — across roughly 6.5 hours. Reviewers consistently say it explains how JavaScript works "under the hood" rather than just syntax.

Will Sentance (Codesmith founder) is the most-praised element. Learners cite his blackboard diagrams, the "backpack" analogy for closure, and a Socratic, audience-paced delivery. The same intense, repetitive style is the one thing a minority find tiring.

Requires a $39/month Frontend Masters subscription rather than a one-time purchase — strong value if you use the wider catalog, weaker if you only want this one course. The course is included in the standard subscription.

This is a conceptual, exercise-and-whiteboard course, not a project build. There is no portfolio-worthy capstone, which some learners miss. The exercises are effective for drilling mental models but produce no artefact.

The mental models — call stack, closure, the event loop, async behaviour — directly explain bugs developers hit daily. Experienced developers report the course clarified concepts they had used for years without fully understanding.

Eleven lessons covering variables, data types, conditionals, functions, loops, arrays, objects, and iterators — a clean, well-sequenced syntax tour for absolute beginners. The ceiling is scope: it teaches the language in isolation, not the DOM or the browser where most beginners expect to use it.

No single instructor — the curriculum-by-committee model means clear, bite-sized written lessons with instant feedback, but no voice walking you through the why. Strong for syntax drilling, weak for the conceptual glue that turns drills into understanding.

The core lessons are genuinely free, which is the single strongest argument in the corpus. Pro ($24/mo) unlocks the certificate, practice projects, and quizzes. For a syntax intro the free tier alone is hard to beat on price-to-value.

Mini-projects (a whale-speech translator, a console cash register) are fun and confidence-building, but the meatier practice projects sit behind Pro. Reviewers repeatedly note you finish without knowing how to start your own unguided project.

The loudest reservation in the corpus. Exercises run in a sandbox console and focus on syntax, not the DOM — so learners reach the end able to pass challenges but not to wire JavaScript into a real web page without further study.