Grafterizer is a software framework developed to support data workers and data developers in the process of converting raw tabular data into linked data. Grafterizer features a user interface for interactive specification of data transformations along with a back-end for management and execution of data transformations. It aims at helping platform users to transform data from a tabular format into a graph format. The transformation supports both cleaning and graph mapping steps. Transformation steps on rows (add, drop, filter, duplicate detection etc.), columns (add, drop, rename, merge etc.) and entire data set (sort, aggregate etc.) are provided together with visualization of the result after each step.