The goal of this project is to enhance research on people’s selective exposure to news and related information – a factor often linked to polarization, e.g., if people from opposing groups systematically choose information their side already agrees with (i.e., echo chambers). This confirmation bias in selective exposure has the potential to produce further attitude reinforcement and individual-level polarization. More specifically, this project will adapt and extend an open source web-tool previously developed by Leiner, Scherr, and Bartsch to allow scholars to easily set up selective exposure experiments featuring (pre-fabricated) realistically-looking online news environments. Scholars can create their own stimuli/content for these online environments and eventually assess which content users select and how long they process selected content. As the tool comes with an interface to web survey software, selective exposure data can be easily tied to additionally collected self-report data, e.g., on attitudinal polarization and identity. In our current project, we investigate the consequences of source cues (e.g., tabloid vs. quality outlets) and sensationalism on selective exposure to news about polarizing issues in the Netherlands.