3 weeks ago
Anthropic adds invisible watermarks to Claude AI-generated text
Anthropic is a company that builds smart computer programs called AI, and one of its programs is named Claude.
Claude can write stories, answer questions, and make pictures and files for people.
Starting August 2, everything Claude writes will get a secret hidden mark called a watermark.
You cannot see this mark when you read the text, but computers can find it, like a tiny invisible stamp that says a robot made this.
Anthropic is doing this because the European Union, a big group of countries, made a law called the AI Act.
The law says companies must be honest about when a computer creates something.
The hidden marks will work all over the world, not just in Europe.
Files made by Claude will also carry a digital note that shows where they came from and whether they were changed.
This can help teachers, writers, and readers know if a computer wrote something.
But rewriting the text a lot or taking a screenshot of a picture can make the hidden marks disappear.
Anthropic will embed watermarks that are undetectable to the human eye into text generated by its Claude models, applied at the model level across API, Claude, Claude Code, Claude Cowork and Claude Tag outputs.
The move responds to transparency requirements under Article 50 of the European Union's AI Act, and Anthropic says the marks will apply worldwide rather than only in Europe.
Claude models launching from 2 August 2026 will carry the watermarks, with generated files such as .svg, .png and .jpg receiving cryptographically signed provenance metadata under C2PA standards.
Text-based watermarks make AI-generated content machine-identifiable at scale and may survive editing, while signed metadata helps show whether a file was processed using Claude or tampered with.
Limitations remain: heavy paraphrasing can remove text watermarks, screenshots can bypass file metadata, and AI detection tools are not 100 per cent reliable.
- Who
- Anthropic, the AI company behind the Claude family of models and products
- What
- Adding human-invisible, machine-readable watermarks to Claude-generated text and cryptographically signed provenance metadata to generated files such as .svg, .png and .jpg
- Where
- Worldwide, including through cloud platforms AWS, Google Cloud and Microsoft Foundry
- When
- Claude models launching from 2 August 2026; Anthropic announced the feature in help documentation published on its website in early August 2026
- Why
- To comply with transparency requirements under Article 50 of the European Union's AI Act
Backing mandatory AI transparency
Questioning watermark reliability
Effectiveness of watermarks
Backing mandatory AI transparency
Machine-readable watermarks and signed provenance metadata make AI-generated text and files machine-identifiable at scale, a level of certainty that was previously impossible and a new frontier in AI detection.
Questioning watermark reliability
Heavy paraphrasing can remove text watermarks, screenshots can strip image metadata, and AI detection tools are not 100 per cent reliable, so the marks can be manipulated relatively easily.
Where the labelling burden should sit
Backing mandatory AI transparency
EU rules put the obligation on AI providers such as Anthropic and OpenAI to mark AI-generated content with machine-readable techniques, with fines of up to €15 million for non-compliance; Google, OpenAI, Meta and Microsoft have also signed the voluntary Transparency Code.
Questioning watermark reliability
India's IT Rules amendment instead requires users and social media platforms to prominently label synthetically generated information, placing the onus on disclosure by users and platform enforcement rather than on AI developers.
Key facts
- Company
- Anthropic
- Feature
- Invisible text watermarks; cryptographically signed provenance metadata on files (.svg, .png, .jpg)
- Regulation
- Article 50 of the European Union's AI Act (Code of Practice on Transparency of AI-Generated Content)
- Effective from
- Claude models launching from 2 August 2026
- Supported outputs
- API, Claude, Claude Code, Claude Cowork, Claude Tag
- Cloud platforms
- AWS, Google Cloud, Microsoft Foundry
- Provenance standard
- Coalition for Content Provenance and Authenticity (C2PA)
- Non-compliance penalty
- Administrative fines of up to €15 million
Quotes
Anthropic
The AI company Anthropic
“Generated text will carry embedded watermarks, and generated files will include digitally signed provenance metadata where supported.”
livemint.com
“The text-based watermark 'may persist' after the content has been edited.”
indianexpress.com










