The website of a company may be a real and sustainable competitive advantage. However, the quality of web applications does not increase as well as their rapid development. In software engineering many quality models were proposed. Research on website quality is prolific. State-of-the-arts on website quality have already been published. However, due to the productivity of this research field, this paper proposes an update of this literature in order to be able to sketch future research avenues on website quality. We analyze how the current approaches cover the large spectrum of web application quality factors. This paper aims at checking whether the main metrics proposed by researchers can be mapped towards ISO 9126 quality sub-characteristics and how this mapping covers the six main characteristics.