R package QCAGUI. The package QCAGUI continues and complements the package QCA with a graphical user interface written in Javascript, using the package shiny. The interface is cross-platform and opens in a webpage which communicates with R via a local web server. Every click in the interface is reactively transformed into a suitable R command, the result being printed in an output dialog which mimics the R console. In addition to QCA functionality, the interface also provides XY plots and Venn diagrams up to 7 causal conditions, a data browser and various other dialogs to recode and calibrate data. QCAGUI contains an extensive set of functions to perform Qualitative Comparative Analysis: crisp sets (csQCA), temporal (tQCA), multi-value (mvQCA), fuzzy sets (fsQCA), and even coincidence analysis (CNA). QCA is a methodology that bridges the qualitative and quantitative divide in social science research. It uses a boolean algorithm that results in a minimal causal combination which explains a given phenomenon.