This program creates a subfolder with randomised numbered filenames and an excel sheet so that the new filenames can be tracked but to the original names. This is useful for blinded studies that involve images and other types of data. To run the filename randomiser program MATLAB 2020a runtime is required and can be downloaded from the following link; https://uk.mathworks.com/products/compiler/matlab-runtime.html or https://ssd.mathworks.com/supportfiles/downloads/R2020a/Release/4/deployment_files/installer/complete/win64/MATLAB_Runtime_R2020a_Update_4_win64.zip