> When a supported Claude model generates text, it weaves an imperceptible watermark directly into the text itself. You won’t see it, and it doesn’t change the meaning, quality, or readability of Claude’s response.

I'd like to know a lot more about how that works.

A lot of my interactions with Claude return pretty precise text. If I ask it to edit a project and refactor a specific function in several places I know exactly what I want to happen, it will NOT be OK if those refactors have some kind of weird pattern baked into their text to act as a watermark.

I guess this may be covered by this:

> Content generated by Claude may not carry a detectable mark if, for example: [...] The passage is very short, leaving too little text for a reliable signal;

>I'd like to know a lot more about how that works.

My guess is that it works like Gemini's SynthID: by altering the logprobs of the next token.

Like, for every 10th token, instead of outputting the most probable, it outputs the 17th most probable, or something. (Obviously it's way more complicated but I think conceptually this is how it works.) No human will notice this, but a classifier trained on Claude's output will.

So it's not like the watermark is the words "le epic bacon" and Claude will output "le epic bacon" in everything. That would be extremely annoying (and easy to defeat).

It was quick :) … https://claudewatermarkremover.app/

Most likely this method https://arxiv.org/pdf/2301.10226 (EDIT: and Google's SynthID paper which builds on it https://www.nature.com/articles/s41586-024-08025-4)

> I'd like to know a lot more about how that works.

Count load-bearing words using two different algorithms in a belt-and-braces fashion

What happens if someone handwrites a Claude output, then someone uses that handwritten text as a reference. Now you've got a watermarked idea which may have no direct linkage to the usage of Claude.

Maybe there is a reason why Opus 5 produces such word salad conversations

It will just thread some load-bearing seams through the paragraphs.

> have some kind of weird pattern baked into their text to act as a watermark.

public abstract class BaseAnimalBeanFactoryGeneratedFromClaudeFactory

Most likely watermark will be proportional to the input/output ratio, i.e. if you input a long document and ask to make edits, it will not attempt to watermark it. On the other hand, if you provide a tweet and ask it to write an article, that will include watermark. Just a guess (and yes, it feels flawed)

Load-bearing==claude

I can tell you how: Claude produces a huge wall of text with jargon ridden bullshit and invented terms no human subject matter expert would seriously use and overuse.