About Claude Watermark

What this site is for. Anthropic began marking Claude’s text output in August 2026, and the internet filled up with tools promising to remove a watermark nobody outside Anthropic can even detect. This site exists to say what is actually measurable, and to build the one tool that only does the measurable part: it finds the artifacts a chat interface leaves in text you copy out of it, and it refuses to claim anything about the statistical watermark, because no detector for that has been released to anyone.

Who runs it. One person: Ofir Smolinsky, an independent software developer based in Israel. There is no team, no editorial board and no staff. Everything published here is written or reviewed by him, and the byline on guides reflects that rather than implying a newsroom.

Who pays for it. Self-funded. There are no investors, no sponsors, no advertising, and no affiliate links or commissions of any kind — including in pages that compare this tool with other people’s. The site earns money one way: some people buy credits for the optional rewriting feature. Checking and cleaning text are free, unlimited, and run in your browser, so they cost nothing to provide and nothing to use.

The conflict of interest, stated outright. This site sells a product in the same category it writes about. That is a real conflict and the honest response is to be checkable rather than to claim neutrality. So: the detection engine is open source and you can read exactly what it looks for; every claim about a competitor on this site is a direct quote from their own page with a link; and the limitation that would most help us to blur — that nobody, us included, can verify Anthropic’s watermark — is stated on the homepage, in the FAQ and in the main explainer.

Affiliation. None. Claude Watermark is not affiliated with, endorsed by, or connected to Anthropic, OpenAI, Google or Turnitin. Claude is a trademark of Anthropic. We have no access to Anthropic’s watermarking key and no private information about it; everything published here comes from Anthropic’s public documentation, published research, or our own measurements.

How to reach a person. Email ofiryieldchain@gmail.com. It goes to Ofir directly and is the same address used for refunds and support. Corrections are welcome and are handled under the editorial policy.