A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Previous portable radios used vacuum tubes, which were bulky, fragile, had a limited lifetime, consumed excessive power and required large, heavy batteries. Following the invention of the transistor in 1947—a semiconductor device that amplifies and acts as an electronic switch, which revolutionized the field of consumer electronics by introducing small but powerful, convenient hand-held devices—the Regency TR-1 was released in 1954 becoming the first commercial transistor radio. The mass-market success of the smaller and cheaper Sony TR-63, released in 1957, led to the transistor radio becoming the most popular electronic communication device of the 1960s and 1970s. Billions had been manufactured by about 2012.
The pocket size of transistor radios sparked a change in popular music listening habits, allowing people to listen to music and other broadcasts on the radio anywhere they went. Beginning around 1980, however, cheap AM transistor radios were superseded initially by the boombox and the Sony Walkman, and later on by digitally based devices with higher audio quality such as portable CD players, personal audio players, MP3 players and smartphones, many of which contain FM radios. Transistor radios continue to be built and sold for portable and in-car use but the term "transistor" is no longer used in marketing as virtually all modern technology makes use of transistors.