For many years it has only been HTML, CSS, and JavaScript that have been native to the Web. In December 2019, WebAssembly joined them as the fourth language to run natively on the Web. This thesis compared WebAssembly to the technologies ActiveX, Java applets, Asm.js, and Portable Native Client (PNaCl) in terms of their performance, security, and browser support. The reason why this was an interesting topic to investigate was to determine in what areas WebAssembly is an improvement over previous similar technologies. Another goal was to provide companies that still use older technologies with an indication as to whether or not it is worth upgrading their system with newer technology. To answer the problem, the thesis mainly focused on comparing the performance of the technologies through a controlled experiment. The thesis also aimed at getting a glimpse of the security differences between the technologies by the use of a literature study. The thesis showed that PNaCl was the technology with the best performance. However, WebAssembly had better browser support. Also, PNaCl is deprecated while WebAssembly is heavily supported and could potentially be further optimized.