Service-oriented computing (SOC) has been widely used by software industry for building distributed software applications that can be run in heterogeneous environments. It has also been required that these applications should be both high-quality and adaptable to market changes. However, a major problem in this type of applications is its growth; as the size and complexity of applications increase, the probability of duplicity of code increases. This problem could have a negative impact on quality attributes, such as performance, maintenance and evolution, among others. This paper presents a web tool called VizSOC to assist software developers in detecting refactoring opportunities in service-oriented applications. The tool receives WSDL (Web Service Description Language) documents, detects anti-patterns and suggests how to resolve them, and delivers a list of refactoring suggestions to start working on the refactoring process. To visualize the results in an orderly and comprehensible way, we use the Hierarchical Edge Bundles (HEB) visualization technique. The experimentation of the tool has been supported using two real-life case-studies, where we measured the amount of anti-patterns detected and the performance of clustering algorithms by using internal validity criteria. The results indicate that VizSOC is an effective aid to detect refactoring opportunities, and also allows developers to reduce effort along the detection process.