Mp3tag is a metadata editor for audio files. It reads and writes the tags that music players and libraries display, such as artist, album, title, track number, year and embedded cover art. It can change those tags across many files in one operation. Mp3tag runs on Windows, where it is freeware for private use and for commercial use that does not involve selling it. Mp3tag for Mac is a separate paid app with a free 7-day trial.
Tag formats and supported files
Each audio format stores metadata in its own container, and Mp3tag writes whichever ones that format allows. MP3 files can carry ID3v1, ID3v2 and APEv2 tags. FLAC, Ogg Vorbis, Opus and Speex use Vorbis Comments. MP4-family files (M4A, M4B, M4V) receive iTunes-style MP4 metadata, WMA files get Windows Media tags, and WAV files can hold RIFF INFO and ID3v2. Monkey’s Audio, WavPack, TAK and similar formats use APEv2. Mp3tag also covers Matroska and WebM files.
For MP4 files, Mp3tag also edits iTunes-specific fields such as the media type and TV show information, which decide how a file is filed in Apple’s media library. Both the interface and the tags support Unicode.
Editing many files at once
The main window has a file list on one side and a tag panel on the other. Users load a folder by opening it or dragging files onto the window. They can add further folders to the same list. Columns show tag values and file properties, and users can edit them in place.
Selecting several files changes how the tag panel behaves. A field that holds the same value in every selected file shows that value; a field that differs shows < keep >. Typing into that field gives all selected files the new value, while fields left at < keep > stay untouched. A whole album can get one year in a single edit while each track keeps its own title. Users add cover art to the panel’s cover area by drag and drop.
A filter narrows the list for larger libraries. Plain text matches anything in tags or file names, and expressions target fields: albumartist MISSING lists files without an album artist, artist IS "..." requires an exact match.
Online album lookups
Mp3tag can fill tags and cover art from online music databases, with Discogs and MusicBrainz as the standard sources. The lookup works per album rather than guessing unknown files. The user enters artist or album details and picks the right release from the results (MusicBrainz results include a match score). The user then reviews the data before Mp3tag writes it.
In that review window, checkboxes decide which fields and which cover image to import. Users can reorder tracks by drag and drop if the database order does not match the files. Mp3tag can suggest an order by comparing titles to file names or track lengths to file durations. Further sources can be added as Web Source scripts.
Converting between tags and file names
Several converters move information between tags, file names and text, all driven by format strings that combine placeholders like %artist% with plain text and scripting functions.
- Tag to file name renames files from their tags. The pattern
$num(%track%,2). %title%produces names like “01. Title”. A backslash in the pattern creates folders, so files can be sorted into artist and album directories during the rename. - File name to tag works the other way, reading parts of the file name and its parent folders into fields. A pattern such as
%artist%\[%year%] %album%\%track% - %title%takes the artist from one folder level and the year and album from the next. The%dummy%placeholder skips text that should not become a tag. - Text file to tag imports a track listing or CSV file, one line per audio file, matched by position or by file name or path.
- Tag to tag copies one field into another or composes a new value from several fields.
An auto-numbering wizard writes track and disc numbers, optionally with totals, and can start a new disc number when the folder changes.
Actions and action groups
Actions handle repetitive cleanup: case conversion, text replacement with or without regular expressions, splitting a field by a separator, removing or merging duplicate fields, and importing, exporting or adjusting cover art. A single action can be run immediately on the selection. Users can save several actions as an action group, which runs them in order. A routine such as tidying capitalization and stripping unwanted fields then takes one click. Mp3tag for Mac supports action groups as well, along with resizing and changing the image format of embedded artwork.
Exports, reports and playlists
The export function turns tag data into text files such as HTML pages, RTF documents or CSV sheets. Each export uses a configuration file that serves as a template, combining text, placeholders and loop functions that iterate over the files sorted by a field. Output can be split, for example into one HTML list per album artist. Mp3tag can also export embedded covers in batches and create playlists from the files in the list.
