Now Claude creator Anthropic says new models will actually mark AI-generated content from launch. Specifically, Claude models launched in the EU on or after 2 August 2026 will support machine-readable marking, with generated text carrying embedded watermarks and supported files carrying digitally signed provenance metadata. Anthropic claims it is also working to add marking to older Claude models. Basically, this means that Claude-generated text will include an invisible watermark. Anthropic explains the watermark is woven into the text itself, does not affect meaning, quality or readability, and can travel with the text when it is copied and pasted elsewhere.