Modern web applications are interactive. Reactive programming languages and libraries are the state-of-the-art approach for declaratively specifying these interactive applications. However, programs written with these approaches contain error-prone boilerplate code for efficiency reasons. In this paper we present PixieDust, a declarative user-interface language for browser-based applications. PixieDust uses static dependency analysis to incrementally update a browser-DOM at run- time, without boilerplate code. We demonstrate that applications in PixieDust contain less boilerplate code than state-of-the-art approaches, while achieving on-par performance.