MapLogger: A Client-Side Tool for Logging User Interaction in Web Map Usability Studies

Interactive web maps are highly dynamic systems, and usability cannot be adequately assessed from task outcomes or post-test questionnaires alone (Vanicek et al., 2026).In such environments, it is also necessary to understand how users actually interact with the interface: which controls they activate, how they navigate, and how their actions unfold over time.This contribution introduces MapLogger, a lightweight client-side tool developed to support usability studies of existing web-based cartographic applications by systematically recording user interactions (and potentially linking them with eye-tracking or other data).MapLogger was designed to reduce the technical barrier to behavioural data collection in cartographic experiments.Rather than requiring a bespoke back-end or manual modifications to individual pages, the tool enables researchers to upload an existing web map project as a ZIP file, define participant tasks, and generate a ready-to-run study directly in the browser (Figure 1).The resulting study package preserves the original project structure while adding a task interface, interaction logging, and CSV export.The logged data include timestamps, task context, event types, selected interface-element attributes, cursor coordinates, viewport dimensions, and other interaction-specific parameters.A companion Analyser then supports rapid inspection of the resulting logs through summary statistics and visual analytics.The practical value of MapLogger is demonstrated through a case study focused on the web application 3D-Geo-Vis, which presents seven methods for interactive 3D visualisation of air temperature data (Zejdlik & Vozenilek, 2025).In this study, MapLogger was deployed alongside eye-tracking and the User Experience Questionnaire (UEQ) with 54 participants completing five tasks.The case study shows how interaction logs help interpret gaze behaviour more robustly, particularly in situations where eye-tracking alone cannot determine whether a user merely considered an interface element or actually activated it.MapLogger provides a transferable, privacy-conscious workflow for cartographic usability research.Because the entire pipeline runs locally in the browser, it is easy to deploy and avoids server-side data handling.At the same time, the paper discusses current limitations, especially the reduced semantic interpretability of interactions occurring inside canvas-or WebGL-based environments.Overall, MapLogger broadens the methodological toolkit for evaluating interactive cartographic visualisations and supports richer integration of behavioural and visual-attention data.The MapLogger tool is freely available at: https://vanicektomas.github.io/maplogger/