Fair use (when copyright law allows use)
Japanese フェアユース
Fair use is a legal exception that lets someone use a copyrighted work without permission under certain conditions. It is the test used to ask whether training generative AI on works is allowed.
Fair use is a legal exception: using someone else's work without permission is not treated as infringement if certain conditions are met. Think of an emergency exit in a door that is normally locked; it opens only when the conditions fit. The test looks at four things together: the purpose and character of the use, the nature of the work, how much of it is used, and the effect on the market for the work. The same test is used when asking whether generative AI may learn from works.
Watch out Fair use is not a permit to use anything. Commercial use alone does not rule it out, but the four factors are weighed case by case, so results differ. Korea's guide covers the AI training stage only and is reference material, not a court ruling. When you put AI output on your website or in ads, check separately whether it looks like an existing work.
Source: Korea Ministry of Culture, Sports and Tourism press release; Asia Economy report; U.S. Copyright Office, 17 U.S.C. 107