An original net animation or ONA is an anime that is directly released onto the Internet. ONAs may also have been aired on television if they were first directly released on the Internet. The name mirrors original video animation, a term that has been used in the anime industry for straight-to-video animation since the early 1980s. The Internet is a relatively new outlet for animation distribution that has been made viable by the increasing amount of streaming media websites in Japan.
A growing number of trailers and preview episodes of new anime have been released as ONA. For example, The Mastermind of Mirage Pokémon (which was available through the Japanese official website from October 13–30, 2006) and the anime movie of Megumi can be considered ONAs.
ONAs tend to be shorter than traditional anime titles, sometimes lasting only a few minutes.