# Claude Will Soon Leave a Hidden Mark on Everything It Writes

> Source: <https://firethering.com/anthropic-claude-ai-watermarking/>
> Published: 2026-08-11 17:36:24+00:00

Anthropic is adding invisible watermarks to text generated by Claude, and unlike a visible label, the marking is designed to travel with the text when users copy and paste it elsewhere.
The move comes as AI-generated content becomes harder to distinguish from human writing and as the European Union begins requiring AI companies to make generated or manipulated content machine identifiable.
Anthropic says the marking happens at the model level, meaning it can follow Claude-generated text across different products and surfaces rather than being tied to a particular app. The company also says it may survive some editing.
But it raises a question, can AI-generated text actually be made traceable once it leaves the model that created it?
And Anthropic's approach suggests the answer may be more complicated than simply adding a hidden signature to every sentence.
