Why Anthropic’s AI watermark is going further than its rivals — for now

Anthropic CEO Dario Amodei and OpenAI CEO Sam Altman.

Chris Ratcliffe/Bloomberg via Getty Images; Eric Lee/Bloomberg via Getty Images Anthropic's push to label AI-generated text may be going further than what its rivals are doing.

Its watermark can survive some edits and has prompted backlash.

"Anthropic is using a sledgehammer that hits simple proofreading and translation," one policy expert said.

Anthropic's new watermark for AI-generated text struck a nerve for some Claude users — but did Europe's laws require it to go as far as it did? A Business Insider review of the law, supported by interviews with AI and policy experts, suggests Anthropic's approach may go beyond what the EU requires.

Under the European Union's Article 50(2), AI companies do not have to mark AI outputs when the technology is used for standard editing or does not substantially change a user's original words or meaning.

Anthropic's watermark, which is designed to remain detectable when text is copied and pasted, can appear in translations, summaries, and more extensively edited text.

"Basically, Article 50 called for a scalpel to catch deepfakes and mass synthetic generation, but Anthropic is using a sledgehammer that hits simple proofreading and translation," Caroline De Cock, senior fellow at the Lisbon Council think tank and head of research at the Information Labs, told Business Insider.

Anthropic has said it is introducing the watermark to comply with the EU's AI Act and that it's rolling it out globally because it does not have a way to apply it on a per-region basis.

While some have welcomed the transparency that AI watermarks can bring, Anthropic's announcement also triggered a wave of backlash.

Some Claude users said they canceled their subscriptions , and developers have created new tools to remove the watermarks .

A recurring concern is that the watermark could be interpreted as indicating that Claude wrote the text, even if only used for editing or proofreading.

This is due to the technical approach behind Anthropic's watermark: it guides Claude's word choices to create a detectable pattern, indicating that the chatbot was likely involved in writing the text.

Lighter editing with Claude is less likely to trigger the watermark, an Anthropic spokesperson told Business Insider, because "there's very little (if anything) for the watermark to attach to." New Claude models will have the watermark, and older models will have it by December.