OpenAI adds opt-in text watermarking for API and EU ChatGPT and Codex output

OpenAI is rolling out text watermarking for EU AI Act compliance, with opt-in access for API customers globally on select models starting today.

Watermarking stays off by default in the API, while an invisible watermark will be added to eligible ChatGPT and Codex text in the European Union over the coming weeks.

Access to the text watermark detector is initially limited to approved researchers and expert organizations, and the image and audio verification tools remain publicly accessible.