M3UM3U M3U M3U ("MP3 URL" or Moving Picture Experts Group Audio Layer 3 Uniform Resource Locator in full) is a computer file format for a multimedia playlist. One common use of the M3U file format is creating a single-entry playlist file pointing to a stream on the Internet. The created file provides easy access to that stream and is often used in downloads from a website, for emailing, and for listening to Internet radio. Although originally designed for audio files, such as MP3, it is commonly used to point media players to audio and video sources, including online sources. M3U  was originally developed by Fraunhofer for use with their Winplay3 software, but numerous media players and software applications now support the format. Careless handling of M3U playlists has been the cause of vulnerabilities in many music players such as VLC media player, iTunes, Winamp, and many others. File format. There is no formal specification for the M3U format; it is a de facto standard. An M3U file is a plain text file that specifies the locations of one or more media files. The file is saved with the "m3u" filename extension if the text is encoded in the local system 's default non-Unicode encoding (e.g., a Windows codepage), or with the "m3u8" extension if the text is UTF-8 encoded. Each entry carries one specification. The specification can be any one of the following: Each entry ends with a line break which separates it from the following one. Furthermore, some devices only accept line breaks represented as codice_1, but do not recognize a single codice_2. Extended M3U. The M3U file can also include comments, prefaced by the "#" character. In extended M3U, "#" also introduces extended M3U directives which are terminated by a colon ":" if they support parameters. Apple used the extended  M3U format as a base for their HTTP Live Streaming (HLS) which was documented in an Independent Submission Stream RFC in 2017 as RFC 8216. Therein, a "master playlist" references segment playlists which usually contain URLs for short parts of the media stream. Some tags only apply to the former type and some only to the latter type of playlist, but they all begin with codice_3. M3U8. The Unicode version of M3U is M3U8, which uses UTF-8-encoded characters. M3U8 files are the basis for the HTTP Live Streaming (HLS) format originally developed by Apple to stream video and radio  to iOS devices, and which is now a popular format for adaptive streaming in general. The 2015 proposal for the HLS playlist format uses UTF-8 exclusively and does not distinguish between the "m3u" and "m3u8" file name extensions. Internet media types. The only Internet media type registered for M3U and M3U8 is codice_4, registered in 2009 and only referring to the playlist format as used in HLS applications. The current proposal for the HLS playlist format acknowledges two media types which it treats as equivalent: codice_4 and codice_6. Likewise, these are the two types recommended for HLS use by Microsoft . For non-HLS applications, no media types were standardized or registered with the IANA, but a number of media types are nonetheless associated with the historical and ongoing use of the M3U and M3U8 formats for general playlists: These types, plus codice_4 and codice_12, are supported for HLS applications by (for example) Microsoft's Windows 10 and Internet Explorer 9, and LG's WebOS. This is an example of an extended M3U file on the Windows platform. Sample.mp3 and Example.ogg are the media files. 123 and 321 are the lengths in seconds. A length of -1 or 0 may be  used when the media file is a streaming file, as there is no actual, predefined length value. The value after the length is the title to be shown, which is generally the same as the location of the file which is on the second line. On the macOS and Linux platforms, Unix paths are used. Examples. #EXTM3U This example shows how to create an m3u file linking to a specified directory (for example, a flash drive, or CD-ROM). The m3u file should contain only one string: the path to the directory. After starting, the media player will play all  contents of the directory: Here is another example, using relative format. The M3U file is placed in the same directory as the music, and directories must be preserved when moving the playlist to another device if subdirectories are used. This method is more flexible, as it does not rely on the file path staying the same. This is the same file as above, saved as sample.m3u in C:\Documents and Settings\User\My Music\ This format in an M3U allows copying to another device for playback. All files and directories referred to must also be copied. Here is a mixed example: Notes: References  to other M3U playlists, for example, are generally not well-supported. The following is an example of a M3U playlist file for "Jar of Flies" album by "Alice in Chains" that was created by Mp3tag with the following custom option settings: Software. Tag editors. The following tag editor software allows users to edit the ID3 tags in MP3 files, and has support for creating M3U files. M3U M3U ("MP3 URL" or Moving Picture Experts Group Audio Layer 3 Uniform Resource Locator in full) is a computer file format for a multimedia playlist. One common use of the M3U file format