These functions can be applied to selected files via the right-click context menu of the File List and are listed under Utils.

Remove Tag Types

MP3

This function opens a dialog displaying the tag types available for removal. To remove specific tag types, enable the corresponding checkboxes and click Remove.

Be cautious when removing tag types such as APEv2, as they may contain metadata like MP3GAIN_UNDO used for volume normalization. Deleting these tags will permanently erase this information. While this does not affect audio quality, it prevents you from reverting volume changes.

Undo information is kept, but only for the currently displayed tag type. When performing an undo, Mp3tag writes the tag types currently enabled under Options → Tags → Mpeg.

Remove Unsupported Fields

MP3

This function removes unsupported fields, i.e., metadata entries present in the files that have no visual representation in Mp3tag. The fields are permanently removed.

If you want to inspect the internal identifiers of those unsupported fields, you can use the %_id3v2_unknown_frames% technical information field, e.g., by adding a dedicated column for that to the File List.

Optimize

FLAC

This function ensures that 4KB of padding exists in the FLAC file. It’s especially helpful if metadata isn’t displayed in Windows Explorer, because either the embedded cover or the embedded padding is too big to handle.

MP4

This function permanently removes all free MP4 atoms (unused space in the file) and puts the moov and tags atoms before the actual audio data.

Strip Chapters

MP4

This function permanently removes chapters from MP4 files.