MP3
open standard lossy compression format for digital audio
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is an audio coding format developed largely by the Fraunhofer Society in Germany under the lead of Karlheinz Brandenburg. It was designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners; for example, compared to CD-quality digital audio, MP3 compression can commonly achieve a 75–95% reduction in size, depending on the bit rate. In popular usage, MP3 often refers to files of sound or music recordings stored in the MP3 file format (.mp3) on consumer electronic devices.
MPEG-1 Audio Layer III was originally defined in 1991 as one of the three possible audio codecs of the MPEG-1 standard (along with MPEG-1 Audio Layer I and MPEG-1 Audio Layer II). All three options were retained and further extended—defining additional bit rates and support for more audio channels (supporting surround sound—in the subsequent MPEG-2 standard).
MP3 as a file format commonly designates files containing an elementary stream of MPEG-1 Audio or MPEG-2 Audio encoded data. Concerning audio compression, which is its most apparent element to end-users, MP3 uses lossy compression to reduce precision of encoded data and to partially discard data, allowing for a large reduction in file sizes when compared to uncompressed audio.
The combination of small size and acceptable fidelity led to a boom in the distribution of music over the Internet in the late 1990s, with MP3 serving as an enabling technology at a time when bandwidth and storage were still at a premium. The MP3 format soon became associated with controversies surrounding copyright infringement, music piracy, and the file-ripping and sharing services MP3.com and Napster, among others. With the advent of portable media players (including MP3 players), a product category also including smartphones, MP3 support became near-universal and it remains a de facto standard for digital audio despite the creation of newer coding formats such as AAC and FLAC.
History
The Moving Picture Experts Group (MPEG) designed MP3 as part of its MPEG-1, and later MPEG-2, standards.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 31, 2026. The linked authority identifier is Q42591. The Library of Congress control number is sh00000865. 2 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1991.
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This entry incorporates text from “MP3” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.