One of the advantages of web surveys is the availability of simple and effective collection of paradata, i.e. data about the process of data collection. Widespread availability of client-side technologies in modern web browsers offers a range of different types of these data. Their utilization and analysis can significantly contribute to understanding the response process and thus identification of potential data quality problems at the level of individual respondents and the survey as a whole. In this paper we scrutinize the use of different possibilities of automatically collected paradata for evaluation of data quality in web surveys. We implemented an advanced paradata collection solution that offers a number of different paradata related to: time (total and first-visit page times, estimated answering times at the question level), questionnaire routing (tracking across pages, returns in the questionnaire), notifications to respondents (frequency and location of item nonresponse and quality check reminders), indications of response-order effects across several questions, multitasking during responding and others. We analyze the relations between these paradata, questionnaire characteristics and response quality indicators across a number of surveys conducted within our research organization. In addition, a dedicated web questionnaire with different question types, logical controls and other features for data quality estimation was conducted. The paper begins with a discussion of technological, methodological and ethical aspects of potentials and problems of using advanced automatically collected paradata in web surveys. It then focuses on analysis of empirical data and presents the power of paradata for understanding the response process and estimation of measurement data quality. Finally, possible future developments of web survey paradata collection and uses are outlined.