EPs were released in various sizes in different eras. The earliest multi-track records, issued around 1919 by Grey Gull Records, were vertically cut 78 rpm discs known as "2-in-1" records. These had finer than usual grooves, like Edison Disc Records. By 1949, when the 45 rpm single and 331⁄3 rpm LP were competing formats, seven-inch 45 rpm singles had a maximum playing time of only about four minutes per side.
Partly as an attempt to compete with the LP introduced in 1948 by rival Columbia, RCA Victor introduced "Extended Play" 45s during 1952. Their narrower grooves, achieved by lowering the cutting levels and sound compression optionally, enabled them to hold up to 7.5 minutes per side—but still be played by a standard 45 rpm phonograph. These were usually 10-inch LPs (released until the mid-1950s) split onto two seven-inch EPs or 12-inch LPs split onto three seven-inch EPs, either sold separately or together in gatefold covers. This practice became much less common with the advent of triple-speed-available phonographs.
Some classical music albums released at the beginning of the LP era were also distributed as EP albums—notably, the seven operas that Arturo Toscanini conducted on radio between 1944 and 1954. These opera EPs, originally broadcast on the NBC Radio network and manufactured by RCA, which owned the NBC network then, were made available both in 45 rpm and 331⁄3 rpm. In the 1990s, they began appearing on compact discs. RCA also had success in the format with their top money earner, Elvis Presley, issuing 28 Elvis EPs between 1956 and 1967, many of which topped the separate Billboard EP chart during its brief existence.
During the 1950s, RCA published several EP albums of Walt Disney movies, containing both the story and the songs. These usually featured the original casts of actors and actresses. Each album contained two seven-inch records, plus a fully illustrated booklet containing the text of the recording so that children could follow along by reading. Some of the titles included Snow White and the Seven Dwarfs (1937), Pinocchio (1940), and what was then a recent release, the movie version of 20,000 Leagues Under the Sea that was presented in 1954. The recording and publishing of 20,000 was unusual: it did not employ the movie's cast, and years later, a 12 in 33⅓ rpm album, with a nearly identical script, but another different cast, was sold by Disneyland Records in conjunction with the re-release of the movie in 1963.
Because of the popularity of 7" and other formats, SP (78 rpm, 10") records became less popular and the production of SPs in Japan was suspended in 1963.
In the 1950s and 1960s, EPs were usually compilations of singles or album samplers and were typically played at 45 rpm on seven-inch (18 cm) discs, with two songs on each side.
Other than those published by RCA, EPs were relatively uncommon in the United States and Canada, but they were widely sold in the United Kingdom, and in some other European countries, during the 1950s and 1960s. Record Retailer printed the first EP chart in 1960. The New Musical Express (NME), Melody Maker, Disc and Music Echo and the Record Mirror continued to list EPs on their respective singles charts. The Beatles' Twist and Shout outsold most singles for some weeks in 1963. When the BBC and Record Retailer commissioned the British Market Research Bureau (BMRB) to compile a chart it was restricted to singles and EPs disappeared from the listings.
In the Philippines, seven-inch EPs marketed as "mini-LPs" (but distinctly different from the mini-LPs of the 1980s) were introduced in 1970, with tracks selected from an album and packaging resembling the album they were taken from. This mini-LP format also became popular in America in the early 1970s for promotional releases, and also for use in jukeboxes.
Stevie Wonder included a bonus four-song EP with his double LP Songs in the Key of Life in 1976. During the 1970s and 1980s, there was less standardization and EPs were made on seven-inch (18 cm), 10-inch (25 cm) or 12-inch (30 cm) discs running either 331⁄3 or 45 rpm. Some novelty EPs used odd shapes and colors, and a few of them were picture discs.
Alice in Chains was the first band to ever have an EP reach number one on the Billboard album chart. Its EP, Jar of Flies, was released on January 25, 1994. In 2004, Linkin Park and Jay-Z's collaboration EP, Collision Course, was the next to reach the number one spot after Alice in Chains. In 2010, the cast of the television series Glee became the first artist to have two EPs reach number one, with Glee: The Music, The Power of Madonna on the week of May 8, 2010, and Glee: The Music, Journey to Regionals on the week of June 26, 2010.
In 2010, Warner Bros. Records revived the format with their "Six-Pak" offering of six songs on a compact disc.
EPs in the digital and streaming era
Due to the increased popularity of music downloads and streaming beginning the late 2000s, EPs have become a common marketing strategy for pop musicians wishing to remain relevant and deliver music in more consistent timeframes leading to or following full studio albums. In the late 2000s to early 2010s, reissues of studio albums with expanded track listings were common, with the new music often being released as stand-alone EPs. In October 2010, a Vanity Fair article regarding the trend noted post-album EPs as "the next step in extending albums' shelf lives, following the "deluxe" editions that populated stores during the past few holiday seasons—add a few tracks to the back end of an album and release one of them to radio, slap on a new coat of paint, and—voila!—a stocking stuffer is born." Examples of such releases include Lady Gaga's The Fame Monster (2009) following her debut album The Fame (2008), and Kesha's Cannibal (2010) following her debut album Animal (2010).
A 2019 article in Forbes discussing Miley Cyrus' decision to release her then-upcoming seventh studio album She Is Miley Cyrus as a trilogy of three EPs stated: "By delivering a trio of EPs throughout a period of several months, Miley is giving her fans more of what they want, only in smaller doses. When an artist drops an album, they run the risk of it being forgotten in a few weeks, at which point they need to start work on the follow-up, while still promoting and touring their recent effort. Miley is doing her best to game the system by recording an album and delivering it to fans in pieces." Major-label pop musicians who had previously employed such release strategies include Colbie Caillat with her fifth album Gypsy Heart (2014) being released following an EP of the album's first five tracks known as Gypsy Heart: Side A three months prior to the full album; and Jessie J's fourth studio album R.O.S.E. (2018) which was released as four EPs in as many days entitled R (Realisations), O (Obsessions), S (Sex) and E (Empowerment).