Evolution of computer networking applications over time has affected the lifestyles of computer users and provided people who are self-learning through a website with a great deal of resources and benefits. This research discusses the characteristics, performances and operating behaviors of web-based self-learners using the computer networking application of online live-streaming platform in an informal learning environment. The first three levels of Kirkpatrick's four-level evaluation model were adopted to evaluate learning effects on web-based learners who were non-formally studying digital image processing knowledge and software operation skills. The results indicated that web-based self-learners experienced positive learning outcomes in the aspects of reaction, learning and behavior.