The interest for user experience (UX) and usability in libraries has grown rapidly over the past years and has now become an essential tool for developing and assessing a library’s digital services and physical spaces. At Linköping University Library (LiUB) we are slowly moving towards a user-centered culture, where users are being observed interacting with both physical and virtual spaces, but this article will only focus on the library’s online presence. The main objective is to argue for continuous usability testing as a part of regular library activity.