If you’re referring to coding “best practices” and actual demonstration of skill by the instructors, some of the instructors on Udemy are certainly better than others. I’ve completed (or partially done) about 20 courses so far by different instructors, and even out of that tiny sample size, have found that in general, the not-so-good instructors vastly outnumber the better ones—and some of these not-so-good instructors have pretty bad holes in their knowledge too!
This is mostly because Udemy does absolutely no “vetting” of the instructors who offer courses on the platform—they’ll host a course by anyone who uploads one, whether that person actually knows the topic or not, or is a qualified instructor or not (and remember: just because someone is a good developer doesn’t automatically mean they’re also a good instructor—I’ve run into some “instructors” on Udemy that I’m sure are good developers but can’t teach to save their lives!). This point cannot be repeated enough, and is the major contributing reason why course quality varies so much on Udemy.
If your question is more of wanting to know if completing certain courses on Udemy are good enough to learn pro-level skills, I’d say this is definitely not the case. Even the best courses that I’d recommend on Udemy often don’t showcase skills that you need to learn as either a front-end or back-end (or full-stack) developer. So yes, even doing the top few courses that I’d recommend on Udemy is still just absolutely scratching the surface.
For example, 3 of the top courses that I’d recommend on Udemy are Colt Steele’s “The Web Developer Bootcamp”, Brad Schiff’s “Git a Web Developer Job”, and Andrew Mead’s “Complete React Developer Course”. They’re all great courses and absolutely worth doing, but completing those 3 is still just the beginning towards getting into web development, whether that’s front-end or back-end. They’re only a start to a solid foundation. You need to keep going and learning as much as you can about a ton of different things.
Taking a look at this will reveal a lot of the topics that you should learn: https://github.com/kamranahmedse/developer-roadmap
Furthermore, you should absolutely not be limiting yourself to Udemy’s platform to comprehensively learn web development via online courses. Putting aside other resources like Google and StackOverflow (which are also essential), and books (whether ebooks or in print), there are definitely better platforms for learning web development:
- Lynda / LinkedIn Learning
- SitePoint Premium
- Frontend Masters
- Linux Academy
- MongoDB University (free!)
For the topic of learning HTML5 specifically, you won’t be able to beat Lynda. I haven’t found a better platform than Lynda for learning HTML5 in particular—none of the other platforms have anywhere close to the coverage on HTML5 that Lynda does. It’s worth taking advantage of Lynda’s free 1-month trial to do all of the HTML5 courses by James Williamson, he really knows his stuff and is probably the most qualified individual to teach the topic!