Anthropic will begin embedding invisible watermarks into text generated by its Claude large language model and chatbot in a move designed to satisfy new European Union rules on AI transparency.
"Claude models launched on or after August 2, 2026 support marking at launch. We’re also working to add marking support to Claude models released before that date," the San Francisco based AI giant said in a statement.
The new marking policy includes all of the services provided by Claude, including its consumer app, the developer-facing Claude Platform (API), Claude Code, Claude Cowork and Claude Tag, as well as versions of Claude accessed through AWS, Google Cloud and Microsoft Foundry.
The watermark will either be weaved in as "an imperceptible watermark directly into the text itself" or as metadata, so that when "Claude generates a supported file type, such as a .svg, .png, or .jpg, it will attach signed provenance metadata... [that] signals that a file was processed by Claude and lets you detect whether the file has been tampered with."
Anthropic said the watermark would apply to every region where Claude is offered, not just the EU.
