FRASTA-toolbox is an open-source application for importing, preprocessing, and analyzing three-dimensional fracture-surface scan data. It provides an implementation of the FRASTA workflow, including grid interpolation, masking, alignment, cross-sectional profile analysis, and interactive two- and three-dimensional visualization based on PyQt5 and pyqtgraph. The software supports reproducible fracture-surface analysis and is applicable to research workflows in materials science, tribology, biomedical engineering, and digital forensics.