18 August 2026

Anthropic adds invisible watermarks to Claude text to meet EU rules

Anthropic, the company behind the Claude chatbot, is embedding invisible patterns into text Claude generates so regulators can verify it came from AI, required by the European Union's AI Act.
The watermark works by having Claude make arbitrary choices between similar words (like 'overcast' versus 'grey') guided by a hidden key, creating a detectable pattern that readers cannot see.