The Web has become an essential part of our lives: billions are using Web applications on a daily basis and while doing so, are placing digital traces on millions of websites. Such traces allow advertising companies, as well as data brokers to continuously profit from collecting a vast amount of data associated to the users. At the same time, the users do not have any control of who is collecting their data and when. Even well-known privacy extensions fall short to protect user’s privacy entirely because companies use sophisticated techniques to track users on the Web. At the same time, website owners include a vast amount of third-party content and scripts in their websites, often to measure Web audience or for additional functionalities. However, website owners do not control whether such content is tracking their users. To give users more control over their data and hold website owners accountable for third-party trackers they include, the upcoming EU ePrivacy Regulation will make a significant transformation in the Web tracking ecosystem. ePrivacy will be based on the notion of user’s consent, which will impart users with an increasing control over their data. To technically express user’s consent in a Web browser, W3C has proposed a Do-Not- Track (DNT) standard. A remaining challenge is how the consent can be technically enforced in the existing Web applications without “breaking” them, while at the same time protecting the Web users. PrivaWeb aims at developing new methods for detection of advanced Web tracking technologies and new tools to integrate in existing Web applications that seamlessly protect privacy of users. In this project, we will integrate three key components into Web applications: privacy, compliance and usability. Our research will address methodological aspects (designing new detection methods and privacy protection mechanisms), practical aspects (large-scale measurement of Web applications, browser extensions implementation), and usability aspects (user surveys to evaluate privacy concerns and usability of existing and new protection tools).