Testing of the web-applications is the process of verification of the client-server products, posted on the Internet, which often includes the support of many interdependent elements. The efficiency, profitability and, in general, the user assessment of information systems largely depends on the quality of their design.

Any software error can cause the financial losses of the company, and vice versa- the application of the commonly accepted standards, convenient functional and design demands and solutions leads to the increase in the number of active users.

Testing considers a wide range of distributed system component that interact with an application. It is often impossible to identify the place of error emerging in the network environment without the participation of the qualified expert, as it can happen in any part of the client-server application. During the testing of web-applications, QA engineers take into account the specificity of the product architecture and the interaction between the databases, server part of application, web-services, external components and user interface.

Web application testing service by the experts include:
Functional testing (checking the functional context of the application for the compliance with the requirements and commonly accepted standards).

Testing of the cross-browser and cross-platform compliant (the identification of defects and differences in system behavior during the interaction between the user and the product in different operating systems, browsers and on various devices).
Testing of the web-services (the process of checking services, called by the web application for the correctness of data processing, changes in the object statuses, return of information from the database, etc.).

Integration testing, E2E (the testing of cross-cutting scenarios for the set of interacting subsystems, including the validation of connections and connectivity, preparation of test data in certain components and step-by-step verification of results of the business processes in the entire system).

Usability testing (testing the user-friendliness, detection of defects in the navigation and interface, as well as the excess or lack of information).
Load and stress testing (testing the stability and resistance to the system failures under normal working conditions and peak load for a long time).

Typical process of working with the tested web-application is as follows. The experts run a full functional test and the analysis of system to identify all existing problems. Then they exercise control over the comprehensiveness of their correction at the later stages of development. The working regulation and format of test documentation are developed separately for every project.