6 October 2026
OpenAI adds invisible watermarks to ChatGPT text in EU, optional for API users
First reported
TechCrunch, The Decoder and 1 other ran this on , all on the same day.
- OpenAI is rolling out textGrain, an invisible statistical watermark embedded in ChatGPT and Codex word choices, to EU users over coming weeks to comply with the EU AI Act's requirement that AI-generated text be machine-readable.
- API customers worldwide can opt in to watermarking starting today, unlike Anthropic which makes Claude's watermarks mandatory globally. Detector access is restricted to approved researchers and organizations initially.
Reported by The Decoder, The Verge, TechCrunch