17 August 2026

Anthropic adds invisible watermarks to Claude text to comply with EU law

Anthropic, the company behind the Claude chatbot, is embedding hidden patterns in Claude-generated text that only someone with a special key can detect, to meet European Union AI Act transparency requirements.
The watermarks work by making subtle choices between similar words (like 'overcast' or 'grey') that don't change meaning but collectively create a detectable pattern invisible to readers.