Lost media are media that have become nonexistent, missing, or unavailable to the general public. The term primarily encompasses visual, audio, or audiovisual media such as films, television and radio broadcasts, music, and video games.
Since the advent of streaming media on the Internet, use of the term lost media has concentrated on media that is not available on digital distribution or streaming platforms. Such media—primarily recorded onto magnetic tape in the case of television and radio broadcast masters—may be entirely lost due to the industry practice of wiping (broadcast media was often considered ephemeral and of little historical worth before the rise of home media in the late 1970s). Others are known to exist but are hard to access outside of archives such as the Library of Congress of the United States and private collections. The Lost Media Wiki, a wiki site founded by Daniel "Dycaite" Wilson in 2012, has spearheaded the search for numerous pieces of lost media, primarily obscure or unaired television programs, but also commercials, music, books and video games.
Preservation efforts attempt to avoid the complete loss of works; this is usually done by storing them in archives, one example being the Arctic World Archive, which has been the chosen location for the preservation of the code on public repositories on GitHub along with a wide range of data of interest to multiple companies, institutions and governments; including the Constitutions of Brazil and Norway.
Lost film
Lost works seem to encompass a large portion of silent films made in the United States. A 2013 report made by the United States Library of Congress estimates that 70 percent of silent films made in the United States have been completely lost.
Lost television broadcast
Lost video games
Video games, including digital downloads, often fade from existence when digital game stores close, as demonstrated by the Wii Shop Channel, V Cast Network and the Nintendo eShop on the Wii U and Nintendo 3DS. The infamous P.T., a teaser to the unreleased Silent Hills game, became un-reloadable after its removal from the PlayStation Network within a year. Fans of the game attempted to revive it, but were blocked from doing so due to legal issues with Konami. The Wii U and Nintendo 3DS digital download games Dodge Club Party and Dodge Club Pocket were removed from Nintendo eShop in 2019 and 2022 and became publicly unavailable due to controlling issues. App Stores like Google Play are also known to frequently remove apps and games, which often are not relisted and become unavailable.
Lost electronic data
Data stored in electronic computers risks being lost if it is not frequently migrated into more recent file formats. This happens because as new computer systems are developed and new technologies are built, now obsolete systems may break down over time, leaving the data inside inaccessible. Electronic data preservation is further complicated by the fact that unless an emulator for a given computer system which can decode the data is present at the time of the preservation, the original data may become inaccessible as the original hardware breaks down, as it may depend on the original hardware to be decoded, although in some cases the original data may be recoverable through lengthy reverse engineering work with the objective of understanding the original computer system enough to decode the most original electronic data possible.
Lost Internet media
Media released on the internet, such as livestreams and blog posts, are especially vulnerable to being lost due to a number of issues, such as a website being shut down, it being deleted by the creator without being archived, or never having been archived in the first place.