Fair use
By Gareth HoyleLast updated How we research
Fair use is the US copyright defense that permits some unlicensed uses of protected works, judged case by case under four statutory factors.
Fair use is a defense under US copyright law that allows some uses of a protected work without the owner's permission. Under 17 USC 107 a court weighs four factors: the purpose and character of the use, the nature of the work, the amount used and the effect on the market for the work.
Is AI training fair use?
AI training is fair use in some cases and not in others. In June 2025, Judge William Alsup in Bartz v. Anthropic held that training on lawfully bought books was fair use, and Judge Vince Chhabria in Kadrey v. Meta found fair use on the record before him. In Thomson Reuters v. Ross, the Third Circuit affirmed on September 29, 2026 that copying Westlaw headnotes to train a competing tool was not fair use.
The US Copyright Office's May 2025 report concluded that some training uses will qualify and some will not, with market harm weighing heavily. A data license removes the question for the licensed data, which is one reason buyers pay.
Does the UK or EU have fair use?
The UK and EU have no general fair use defense. UK law has narrower fair dealing exceptions, and EU law relies on the text and data mining exceptions.