As an ID3 tag is called a format for additional information ( metadata) that can be included in audio files of the MP3 format. ID3 stands for Identify to MP3 ( " Identify an MP3 file "); the English term day means something like " labels " or " label ".


Before there was ID3 tags for information such as the name of the album of the artist or music style, had the file or directory name to record this information. The result was a very long file names and therefore confusing directories. In addition, file systems often are not suited for all special characters, which are necessary for some artist, title or album names, as well as for the length of the required file names; also often differ, the character encodings, such as ISO 8859 and Unicode, special characters are interpreted between different codepages of ISO 8859 incorrectly or the file names are corrupted during transmission over a network ( specifically, through the protocols or their implementations).

Therefore it was decided to accommodate this metadata in a reserved portion of audio files.

Based on ID3 is a similar process for image files in JPEG format containing the date and related information, the Exif information, developed.

Operation and history

The MP3 file format meta-information are not present by default. ID3 is also in the latest version ID3v2.4 only an informal standard that has not yet found a way into the MP3 standard. In contrast to newer formats and container formats, there is no distinction between audio and metadata, and therefore has to be found out by pattern recognition if one of the following formats can be considered.

Essentially, there are two major versions of the ID3 tag format ID3v1 and ID3v2, which are described in more detail below.



The first version, ID3v1, was introduced in 1996 by Eric Kemp with the program " Studio3 ". To prevent a playback program or device tries to interpret the ID3v1 data as audio information, they will be added at the end of file.

ID3v1 is kept simple and only consists of a 128 byte block with solid construction:

The character set for the text fields is not specified, usual ASCII, ISO 8859-1 and Unicode, encoded as UTF -8. This can lead to misinterpretation with umlauts and special characters.

The genre of the title is encoded as a single byte. It exists to a list that specifies which value corresponds to which genre.

Although ID3v1 numerous weaknesses had it spread very quickly. The main disadvantages are:

  • No expandability for more information
  • Fixed length of the available data fields: title, artist and album can be encoded with only a maximum of 30 characters.
  • Restriction to the ANSI character set or missing statement about the character encoding of the character strings
  • Data are at the end: For files no problem for streaming, however impractical because the metadata is transferred only at the end of the title.


A further development of ID3v1 standards was difficult, because the existing fields were already set in stone. Michael Mutschler succeeded an extension to ID3v1.1. In the Comments field has been reduced from 30 to 28 bytes. This is followed by a null byte, which ensures that all ID3 Reader stop with the evaluation of the strings. The liberated byte at position 126 was the importance title number.


Due to the weaknesses of ID3v1 was designed in 1998 by Martin Nilsson and others, a new format that was named ID3v2. The additional information is here ( the MPEG stream ) inserted in a block before or since ID3v2.4 even after the audio data in the file. Current version is 4.0 (also ID3v2.4.0 ) from the year 2000.

In the current version 2.4, many supplementary information shall be specified, but there is hardly an implementation that supports the whole functionality. A special feature is, for example, cover images or whole stuff ( together known as album art ) that can be stored in the ID3 tag and are identified by the PIC flag. Maximum 256 MiB large PNG or JPEG images are specified, but between 32 × 32 to 600 × 600 large images stored in the normal case, the appear sharp on modern smartphones.

ID3v2.2, v2.3 and v2.4

Some versions of ID3 tags are incompatible with each other. The main differences are:

  • V1 to v2.2 have been deprecated; few programs write to this day still the default version. Even the basic simple implementability in playback devices or programs no longer speaks for it.
  • From version 2.3 specific character encodings to be used are specified. v2.3 supports the encodings ISO 8859-1 and UTF -16, v2.4 also supports UTF -8.
  • Normally v2 tags are at the beginning of a file, it allows v2.4 but also at the end. So far, however, there are only a few tagging programs, or software or hardware players that support this option.
  • From version 2.4 text attributes such as the genre or the artist can get multiple values ​​. Thus, a song, for example, two genres, and a duet be assigned to both singers, instead of the names manually to a string " Artist A, Artist B" together or " jazz-pop ".

The most widely used version v2.3 is supported by almost all of the newer programs and devices; However, some have problems reading Unicode tags, although the standard specifies this encoding.

UTF- 8 encoded tags of version 2.4 are the newest, most flexible version of the v2 standards. Despite significant progress in recent years the new features of v2.4 are often only partially supported. Thus, with multiple values ​​often only the first appears in text attributes, or values ​​are hung together, so that of the two genres, " Pop " and " Jazz" then as " pop jazz " or " JazzPop " is.

Display of ID3 tags

Most mobile MP3 players can display ID3 tags. In addition, many modern operating systems and work environments have implemented a ID3 support. Under Linux, there are in addition to the command line tools id3 ( for ID3v1 tags) and id3v2 ( for ID3v2 tags) and graphical display and editing options, such as the KDE kfile plugin - see the picture above to Konqueror. In Windows Explorer allows you to view and edit ID3 tags. Apart from these options, most audio players also offer this feature.

Editing ID3 tags

To edit ID3 tags, known as a tag editor is needed. In many playback programs is one such already integrated. In addition, there are a number of specialized editors ( standalone tag editors ) with extended functionality.