Encyclopaedia Britannica sues OpenAI over alleged use of its content to train AI models

Encyclopaedia Britannica and its subsidiary Merriam-Webster have filed a lawsuit against OpenAI in a federal court in Manhattan, accusing the company of improperly using their copyrighted materials to train AI models.

The complaint, reported on 16 March 2026, claims that OpenAI used articles from Britannica’s online encyclopedia as well as dictionary entries from Merriam-Webster to train its large language models, including the chatbot ChatGPT.

According to the lawsuit, OpenAI allegedly copied nearly 100,000 Britannica articles during the training process. The publishers argue that the AI system can generate responses that reproduce their content closely and may divert users away from Britannica’s websites by providing AI-generated summaries instead.

Britannica also claims that ChatGPT sometimes produces responses that appear to attribute information to Britannica without authorisation, and that this may infringe on the company’s trademarks.

OpenAI has responded that its models are trained on publicly available data and that the use of such material falls under fair use because the technology transforms the information into new outputs.

The case is part of a growing number of legal disputes between publishers and AI companies over whether copyrighted materials can be used to train AI systems without permission. Britannica has previously filed a related lawsuit against the AI company Perplexity AI over similar issues.

In the current case, Britannica is seeking financial damages and a court order that would prevent the alleged unauthorised use of its materials in AI systems.