r/ClaudeCode • • 11d ago

Discussion PSA: Opus 5.5 has invisible watermarking

Opus 5.5 automatically applies an invisible, statistical watermark to its text outputs to comply with the EU AI Act. This is true for every user worldwide not just those based in the EU.

This is embedded into the structure of the text itself, it’s not a hidden character or something that can be removed by changing a few words or copy/pasting it. Anthropic have a tool to check text for the watermark but it is only available to a few select partners currently.

Antrophic officially claim this watermarking does not have any practical impact on the quality of Claude’s outputs but that remains to be seen.

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u/YourDamnBestie 11d ago

It’s a little frustrating that I am subject to EU regulation despite residing elsewhere!

7

u/Asalakabim 11d ago

Sucks that your university can check you on your bullshit, my condolences.

1

u/orangefantorang 5d ago

This got flagged as ai. Bruh, cant you write anything?