Anthropic has begun embedding invisible watermarks into everything Claude writes, a move the company says is designed to meet new European Union transparency rules that came into force this month. The change applies to every Claude model launched from 2 August 2026 onwards, across the consumer app, the developer API, Claude Code and Claude Cowork, as well as versions of the assistant offered through AWS, Google Cloud and Microsoft Foundry.
The company confirmed the marking applies globally, not just in Europe. Anthropic said all Claude models launched from 2 August 2026 onwards will include the feature at release, and that it is working to add it to older models.
