How Claude's text watermarking works
Anthropic 27 ● 7 sources
Anthropic will add text watermarking to future Claude outputs to make it possible to assess whether Claude was likely involved, as part of EU AI Act compliance. The change takes effect with the EU requirement dated August 2, 2026. Watermarked text will be indistinguishable to readers, should not affect quality or cost, and will be verified via a later detection API using a cryptographic key rather than user-identifying information.