Load testing and cross-browser testing are ones of the web testing types that heavily rely on the support of cloud computing platforms for realizing the concept of TaaS (Testing as a Service). Although efforts have been made on composing heterogeneous web services, little emphasis has been put on composing heterogeneous web testing tool services and delivering a composite web testing service as a whole. The main challenge involved in the composition of heterogeneous web application testing tools is the incompatibility of their inputs and outputs. However, the need to manually configure the tools greatly undermines the convenience and applicability of their applications. In this paper, we propose a system for the composition and delivery of heterogeneous web testing tools with the following key features: (1) four adapters to automatically bridge the gap between the inputs and outputs of six state-of-the-art testing tools; (2) a composite web testing service with the adapters; and (3) two adapters to enable delivering the composite service via emails. Experimental results demonstrate the effectiveness of the proposed system in reducing the effort required for load testing and cross-browser testing in comparison with a conventional method.