Metadata consist of information that characterizes data. Metadata are used to provide documentation for data products. In essence, metadata answer who, what, when, where, why, and how about every facet of the data that are being documented. Metadata within a file can tell a lot about you. Cameras record data about when a picture was taken and what camera was used. Office documents like PDF or Office automatically adds author and company information to documents and spreadsheets. Maybe you don't want to disclose those information. This is precisely the job of mat2: getting rid, as much as possible, of metadata. mat2 provides a command line tool, and graphical user interfaces via a service menu for Dolphin, the default file manager of KDE, and an extension for Nautilus, the default file manager of GNOME. The following formats are supported: avi, bmp, css, epub/ncx, flac, gif, jpeg, m4a/mp2/mp3/..., mp4, odc/odf/odg/odi/odp/ods/odt/..., off/opus/oga/spx/..., pdf, png, ppm, pptx/xlsx/docx/..., zip, torrent, svg/svgz/..., tar/tar.gz/tar.bz2/tar.xz/..., tiff, wav, wmv, ...