Yes, a software engineer can become a web developer. It is also easy to become a web developer compared to a software developer. There are many less expensive, more time-efficient routes to learn Web development. You could become a web developer after attending online courses for web development. If you are looking for online courses to learn Web Development, I recommend these web development courses by Intellipaat.
If you want to start a career in Web Development, check out these Web Development Online Courses by Intellipaat.
Also, watch this video on Web Development Vs Software Development to know more: