JavaScript.info
The modern JavaScript tutorial, covering the language from basics through prototypes, closures, promises and modules, with exercises and solutions throughout. The clearest free explanation of the parts of JavaScript that confuse people.
Guide
Web Development
Ilya Kantor
2 to 3 months
All
Free
What it is
A free, continuously updated JavaScript tutorial organised in three parts: the language itself, the browser and document model, and a collection of additional topics.
Why it is worth working through properly
Most JavaScript is learned by absorption through a framework, which leaves reliable gaps: prototypes, the behaviour of this, closures, the event loop, and how promises actually schedule. Those gaps surface as bugs that make no sense and as interview answers that fall apart. This covers them in order, with exercises.
How to use it
Do the exercises. It is written well enough that reading feels sufficient, and it is not. The sections on closures, prototypes and the event loop are the ones most worth slowing down for.
Best for: anyone whose JavaScript came from React tutorials, and anyone preparing for a front end interview.
Ready to start?
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Stuck on something specific?
Writing only gets you so far. If you want an answer to your situation rather than the general case, book a session and we will work through it together. Every session is free; a few slots open each week.
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