CTTinShiny provides a graphical user interface (GUI) for conducting Classical Test Theory Analyses (CTT). The GUI is built using Shiny and the CTT package from R. The interface is available below. You can also access it directly from the Shiny Apps web server. If you prefer a local install, you can download the CTTinShiny package from CRAN. Running the package locally requires RStudio and R, as well as a passing knowledge of the R language.