Well, the internet was pretty divided this past week over some changes coming to Claude, as Anthropic recently announced that future Claude models will generate text containing a watermark as part of its efforts to comply with the EU AI Act.
Some people see this as a great way to help detect AI-generated content… others see it as a menace… and in reality, only time will tell whether that watermark helps AI detection. Regardless, we should talk about it.
Claude as a Copywriter
Let’s be fully honest here: a lot of people use Claude for copywriting (or at least as a writing aid), and it is not hard to see why: Claude tends to produce text that reads a little more naturally than some of its competitors (without the annoying break lines that certain ChatGPT likes to add every two words), which makes it one of the go-tos for content that is supposed to sound like a human wrote it.
And yes, nobody likes to admit they use AI to write their content, not even when the use is more for research, but the reality is that a significant chunk of what you read online is written with some sort of AI assistance… and in some cases being fully AI generated, to the point where it has become a real problem on platforms like LinkedIn, which recently introduced a button specifically to report AI slop.
And to be clear: we are not here to tell you whether you should or should not use AI to assist you in your content creation journey. What we will say is that there is a meaningful difference between using it as a tool to brainstorm, check grammar, get a second opinion, or polish a draft and using it as a ghostwriter who does the whole job while you hit publish: The first is a workflow; the second is where things get complicated, and the watermark is aimed squarely at the second.
How Does the Watermark Work?
Well, for starters, we should say this is very different from the “hidden characters” we are used to. The new watermark Claude will be implementing works entirely by influencing which word Claude picks when multiple options would be equally good.
… Ok… maybe that sounds complicated… let us try to explain it in a more digestible way…
Imagine Claude is writing a sentence like “The sky today was cloudy and…” The next word could be “grey” or “gloomy”; both work perfectly fine, and the sentence means the same thing either way… normally Claude would just pick one randomly, but with the watermark, instead of picking randomly, Claude uses a secret key to decide which one to pick.
The key is like a secret recipe that influences those small, unimportant choices, not in a way that changes the meaning, but in a way that leaves a pattern.
Now, if someone later wants to check whether Claude wrote a piece of text, they use that same secret key and look at all those small word choices throughout the text. If the pattern matches what the key would have produced, they can say “yeah, Claude was probably involved in writing this.”
The clever part is that, to the average human reader, nothing looks different (or at least it shouldn’t, but there is always someone, somewhere, who will notice). “Grey” and “gloomy” both make perfect sense, and the average Joe out there would never notice which one was picked or why, but the pattern is there, hidden in hundreds of those tiny decisions made throughout the text.
And that pattern is what makes this both powerful and imperfect.
The Watermark… Good or Bad?
Just like the AI slop button on LinkedIn, the watermark has two very real sides to it. The upside is significant: watermarking allows platforms to identify and label AI-generated content, giving users context they did not have before and that is genuinely valuable in combating misinformation, but it also comes with limitations that are worth understanding before we get too excited.
As Anthropic itself states, using its key doesn’t confirm whether the text was human-written and then edited by Claude, nor can it tell whether another AI wrote the text. Also, it doesn’t work well on small samples (a two-line caption might be harder to detect as AI).
And the implications of that are broader than you might think. Take this very article, for example: if we grab the final article, take it to Claude and ask it to please “review the grammar and provide feedback.” We get good feedback, decide to have the changes applied, and then copy/paste the article back into the blog editor… it does not matter if we wrote the original article word by word on our keyboard; the fact that Claude checked it and then we copy/paste it from there back to the editor could trigger the watermark, but that does not necessary mean you are now always going to be flagged as AI.
When Claude proofreads your text, the watermark only attaches to the words Claude itself chooses. If Claude corrects a handful of grammar mistakes in a 1,000-word article you wrote, the vast majority of the words are still yours, and that may not be enough for the watermark to register at all. The shorter the text and the lighter the edit, the less likely the watermark is to be detectable. The watermark also does not work well on highly factual passages, where there is really only one right word, and Claude has no meaningful choice to make.
Why Does This Matter to You?
If you are a content creator, marketer, or small business owner who uses Claude as a tool, the watermark is not really going to cause you many issues, as light editing is unlikely to leave a strong enough signature to be detected.
If you are using Claude to generate content wholesale and publishing it as your own… well, that is a different conversation. And honestly, not one about the watermark only but one about what you are doing with your online image, how people are actually perceiving you, and who hurt you in the past.
As a reader… well… now you will have an easier way to identify AI-generated text, and hopefully this will help you fact-check the information you read.
The bigger picture here is that Anthropic is not alone in this: as of August 2, 2026, the EU requires AI providers serving its market to mark AI-generated content, and around 190 signatories, including all the major model providers, have signed on. The watermark is coming whether we like it or not, and it is coming everywhere, not just in Europe.
Is it a perfect solution? No. Can it be beaten by rewriting the text? Yes. Are people eventually going to create some sort of “watermark remover online tool? Absolutely. This does not solve the AI slop problem on its own, not even close, but it is one more layer of transparency in a space that has had very little of it, and for now, that is probably a step in the right direction.
