Quality is an essential characteristic for web success. Several authors have described different methodologies, guidelines, techniques and tools in order to assure the quality of web sites. Recently, a wide ranging set of metrics has been proposed for quantifying web quality attributes. However, there is little consensus among them. These metrics are sometimes not well defined, nor empirically or theoretically validated. Moreover, these metrics focus on different aspects of web sites or different quality characteristics, confusing, rather than helping, the practitioners interested in using them. With the aim of making their use easier, we have developed the WQM model (Web Quality Model), which distinguishes three dimensions related to web features, lifecycle processes and quality characteristics. In this paper we classify the most relevant web metrics using this framework. As a result of this classification we obtain that most of the metrics are classified into the “usability / exploitation / presentation” cell. Another conclusion obtained from our study is that, in general, metrics are automated but not validated formally nor empirically which is not a good way of doing things.