Is it illegal to take the company framework at the front end?

May be illegal.

It depends on what you do. It's ok if you only use it for yourself or work for this unit. If you apply for a patent or transfer a patent, it constitutes infringement. In fact, I personally think that whether to use the framework can not be considered from a personal point of view, but should be considered from the staffing, business logic and development time of the project. For example, if you want to make a non-functional display website now, you must give priority to js+html+css. Why do I say that? First of all, this exhibition website itself is for promotion, so SEO and SEM are inevitable, and there is no need for functions such as two-way binding, just a few static pages.

If the framework of vue is used in these websites, it will undoubtedly add unnecessary burden to the websites. But if you want to make a functional website, using a framework is definitely a good choice.