Anthropic is now embedding a machine-readable watermark in Claude's generated text, a change that will apply globally rather than only in the EU. Claude models launched in the EU on or after August 2, 2026 embed the watermark in every piece of generated text automatically; it is invisible to the reader and detectable only by software that knows where to look. Files such as images carry signed C2PA provenance metadata where the format supports it.

The trigger is Article 50 of the EU AI Act, which requires deployers of AI systems generating public-interest text to disclose AI use — the duty falling on the publisher, not the model provider. Anthropic says it is rolling the change out globally because it has no reliable technical way to apply the watermark only inside the EU; the legal duty still only applies to users in or sharing content into the EU. Models already in use before August 2 are getting watermarking support in stages over the coming months.

Anthropic says the change has no effect on output quality: the method statistically biases the words Claude selects during generation, creating a pattern too subtle for a reader to notice. A watermark can't tell you how much human input went into a finished piece, but it gives PR agencies, publishers, and regulators a machine-checkable answer to whether Claude helped write it.