Anthropic's ‘watermark’ text adulteration in Claude is a perversion of writing
daringfireball.net
daringfireball.net
So every check requires sending the text to as many AI providers as offer a watermarking detection API, almost all of which have a very dubious track history with obtaining training data through illicit means.
Any university using AI detection in their submission pipeline, or lawyers, editorialists, proofreaders that check for AI marks will be sending significant amounts of text like unpublished research, books, potentially internal documents and more, most of which is high quality human written, to dozens of AI companies, blindly trusting they won't train on any of that.
I wonder if this would be a good use for homeomorphic encryption. There might be a way to let anthropic check some text without actually giving them access to the source text. Any experts around? We could use your skills!
Uh, yeah, why do you think it's setup this way? The frontier companies desperately desire more high quality human text and this is how they are planning to get it for free.
LLMs cause a wide number of problems, the good news for our investors is that they're all solvable with LLMs.
Couldn’t it be checked in the TEE using confidential computing to keep Anthropic’s algorithm secret?
Local models could probably catch some patterns.
I would think that these things would eventually converge and we’d get one watermarking algorithm as an industry standard. That way, all major provider would follow it and we’d get independent software for checking. This would partly limit the efficacy of the watermarks, but on the other hand if it’s done correctly, removing the mark could still be enough of a pain that casual users would not bother. That would obviously depend on a lot of factors. It would at least add significant friction in the production of daily slop.
Of course it wouldn’t do much for thing like foreign propaganda but that’s a whole other discussion we need to be having.
> Any university using AI detection in their submission pipeline, or lawyers, editorialists, proofreaders that check for AI marks will be sending significant amounts of text like unpublished research, books, potentially internal documents and more, most of which is high quality human written, to dozens of AI companies, blindly trusting they won't train on any of that.
Isn’t it already what they are doing right now with some of the plagiarism detection tools? Not every university is going to have a representative corpus, and yet they are all using the software. So I guess the provider is doing the work of feeding all that data to their algorithm.
I read stacks of term papers all year and it is a reality that, apart from such schemes, we are in an extinction event for civilization.
its also kind of laughable that somehow people are trying to prevent the outputs not to be altered. Asif you cannot manually paraphrase anything you can read. So the only solution would be, to make it utterly unreadable (which is not possible, it obviously defeats the purpose of the thing).
Not to mention local models ofcourse :-)
Having proof that content (especially images and video evidence) is unmodified (whether via Photoshop, Paint or a model) is far more valuable then having evidence that an image was manipulated or generated fully by a model (which still leaves other forms of manipulation), I feel the same goes for human authored vs generated text. Free to admit that using models to generate any kind of media whole-cloth is still unappealing to me and I still pay for commissioned artwork or make it with my limited abilities for what that's worth. Do like to (poorly) write my musings too and see UX as something were thoughtful contributors (like the opinionated, sometimes controversial, but certainly talented GNOME Gitlab contributors) can make a major impact.
Code can be beautiful, interesting and serve purpose beyond execution, of course, but for most people, in most cases, it does not in the same way as audiovisual content (not limited to art). Having code just to execute and resolve a problem can have value all in itself, the code being a means to an end whose quality, let us be honest, was barely a concern in most corporations long before LLMs.
Also have rarely (honestly never) before LLMs fully owned all parts of any code base, always relied in part on someone's prior effort in (Flutter/Dart mostly) packages, whereas when writing, drawing, etc. I have far more situations where I make something from scratch and everything there is only there because of my conscious decision. Even simple marketing mockups that, quality wise, any modern model would beat feel different when I was fully in control, where to place what, etc. Objectively worse (at my skill level), probably, but still never the same.
Knowing something was made from scratch by a human has value to me, beyond misinformation prevention. Knowing for a fact that LLMs were used instead of importing a library, using a template, or something similar that leads to expending similar amounts of effort, I don't see that being nearly as valuable. Heck, with all the importing and my experience back then vs now, I am spending more effort actually fully reading any LLM output in my code then I spent back then auditing Flutter/Dart packages. Then again, LLM output fails far more unpredictable then those messy packages that simply got Gradle to take down my system...
Happy to admit, I have been skeptical of watermarking LLM output being feasible for quite some time and having looked into SynthID Text and proposals being researched, I am convinced that it is challenging to impossible beyond the lowest common denominator and less important then proofing human authorship.
It will catch people just copying LLM output into their replies without thought, which is not a negative in my book, especially if it is not discernibly affecting output quality in regular use cases. Anyone who wouldn't copy Wikipedia into their dissertation will, in my opinion, be able to bypass text watermarking as proposed however, I feel we need to be honest there.
Thing is, if that's the case and text watermarking will only ever catch LLM created slop, is that a bigger problem then the misinformation, harm to creators due to authorship questions and accusations, making it harder to use evidence in proceedings, teachers not trusting students even when they did the work themselves, etc.? Signatures for all such cases will be difficult to implement, yes, but I feel are going to be of greater value in the not to distant future and I equally feel are not impossible, not least because idiots will always want to hide their LLM usage, whereas human authorship is something they take pride in and want to proof.
being allowed to train on any data that you can legally obtain ought to be a right for anyone.
After all, i am allowed to learn off anything i can legally read (and perhaps even illegally read). The only thing not allowed (rightly so) is to produce a copy with enough similarities that it can be replacing the original.
Then bad news: LLMs already use randomness in a fundamental way. Each time they go to generate a token, they first generate a probability distribution of possible tokens. Then they pick one randomly according to this distribution. The technique described can be thought of as making the random number generator pseudo random. The output it generates is one of the possible outputs it would have generated before, just now it's deterministic and will generate the same thing every time.
> To illustrate, in the special case that GPT had a bunch of possible tokens that it judged equally probable, you could simply choose whichever token maximized g [a cryptographic function]. The choice would look uniformly random to someone who didn’t know the key, but someone who did know the key could later sum g over all n-grams and see that it was anomalously large. The general case, where the token probabilities can all be different, is a little more technical, but the basic idea is similar.
(1) The behavior that is approximately what you describe is not "fundamental" (though it may not be something you can disable on some hosted providers), it is an option that is not fundamental (and with runtimes where you have full control can be either disabled or tuned in a large number of manners), and
(2) The actual behavior that is approximately what you describe already usually involves use of PRNG (with a user or harness supplied seed), not a true RNG; the change to do watermarking isn't going from RNG to PRNG, it involves adding an additional set of constraints on token generation on top of the existing ones, which inherently compromises quality.
On the other hand, LLMs are forced into picking some likely-ish word, and then have to build the rest of their response to retcon that choice into making sense.
Even good human writers would probably struggle with this constraint. It would be like someone interrupting your writing to tell you the next word MUST be such-and-such, and then you have to try and make it work as best you can first try, without going back to edit. The result would probably be a little clunky. (Maybe it’s impressive LLMs write as well as they do.)
Watermarking changes the probability calculations for reasons other than quality. It can't not compromise quality. It literally leads the LLM to occasionally chose different tokens just for watermarking purposes.
Even so, I don't think it will stop here. Once this is in place, the next step is to put more and more identification into the AI generated content; might as well pack it in, it's not that bad, and if it is they won't admit it. There's no way for anyone to check. And your argument will still be technically correct but missing the point.
Then write your own damn text if you care about the exact wording so much
I’m willing to venture that Gruber is on the list of folks that get to hold the opinion choice of words matters.
http://blog.tyrannyofthemouse.com/2026/04/open-ai-strikes-ba...
If you want precision and clarity of your writing, then you need to hand write it. Just like when you are optimising, its common to drop to a lower level language because the compiler doesn't express what you want. Sure its hard, but you know, thats kinda the point.
Even if you don't want that, the LLM is an average of the style it was trained to give out. Which is a homogenisation of the language to create a vague padding medium between a few generalised facts. (because a. it makes it less jarring when stuff is wrong, because its smeared over a higher amount of text and b. it looks more 'professional' because American business English is all guff and no meat)
Also yes, two isolated phrases may have subtly different meaning, frankly, the nuance is missed on most people. If you look at the interactions on here, at least 25% of the arguments are caused by people angrily reacting to the things _they_ thought the other person was saying, rather than what the actual person was saying.
So no its not a perversion, the LLM is, if you're gonna be picky about things.
> Marks will apply to output from supported Claude models across Claude Platform (API), Claude, Claude Code, Claude Cowork, and Claude Tag, and wherever Claude is offered.
I've never asked an LLM to generate writing I wish to post as my own. I don't understand why we think it is a good idea to fudge all output just so people can't cheat on their homework or generate slop. It won't have any impact on those things because there will always be models that don't do this. All it will do is increase the rate of false negatives.
It is deeply misguided regulation and Anthropic should have just said no on grounds of common sense.
The problem is, that LLMs worked very well for me to improve my writing. Especially as I'm not a native speaker, it was a great way to improve the legibility of my work.
I want a tool that helps me improve my writing. A tool I can learn from. Not a tool that switches out "bananas" to "airplanes."
I'm was using Claude Opus and now Fabel extensively for editing my texts and I find the recent updates abysmal. Not sure if it's due to the Text Watermark.
Before Claude was great in sharpening the meaning in my writing, it's now close to unusable.
Watermarking per model is just the start. The method is cheap enough to distinguish individual users.
I'm skeptical that anybody generating LLM text is really all that concerned about optimal word choice. Or even particularly good prose. But let's pretend that person exists.
If that person tried, say, an open model and that same model with watermarking applied, I'd be eager to hear their thoughts on the prose quality. Especially if they built an experiment harness and rated a few hundred blinded examples and found a measurable difference.
But getting this upset in advance of any demonstrated problem? It really seems to me like the point isn't the point
I think in this case it doesn't help that there are multiple watermarking schemes, and the easiest for people to understand is the red/green scheme by Kirchenbauer et al. (https://arxiv.org/pdf/2301.10226), which does technically distort the logits (but I'd argue only in cases where you wouldn't notice it anyway).
I wasn't aware of this gumbel softmax scheme, it seems you're referring to https://simons.berkeley.edu/talks/scott-aaronson-ut-austin-o... ? That's really clever as it doesn't even distort the logits, basically cryptographically indistinguishable from a "real" random sample unless you have the key.
The actual scheme Claude uses seems to be neither of those two though, they say it is SynthId-text which seems to be tournament sampling based.
Prove it, then? It's not a claim that GumbelSoft paper makes: "Regarding generation quality (perplexity), GumbelSoft shows relatively low perplexity"
Cognitive surrender.
Sometimes when you're trying to write something, it really seems like the exact words matter a lot. Suggestions made to be more direct or use a more common word here or whatever seem to really impact the thought that you're trying to communicate.
Certainly we've all had times when trying to communicate clearly when the specific words seem very important.
This is not entirely accurate. Sure, there's never a token with 100% certainty, but there are often tokens with 99.9% probability, but this technique of course does not change how such a token is sampled.
Indeed.
It's frankly bizarre to see the assumption to the contrary being made by someone who's been passionately blogging by hand for years, who also happens to be responsible for the notoriously vague, humanistic, DWIMmy Markdown standard.
Can you give an example of something smart John Gruber has said or written? Because I can't think of one, but I can think of many dumb ones.
Gruber made an effort to but doesn't fully understand how SynthID works. LLMs select the next word randomly from a set probability distribution, so there is no "best choice" unless you run the LLM with a temperature of 0 which would give out terrible results. Anthropic runs a non-distorting version of SynthID that doesn't change the probabilities of the underlying distribution of tokens. It makes the watermark less likely to work over smaller samples but preserves text quality. I encourage the mathematically inclined to read the paper:
I'm not understanding how the word with the highest probability isn't the "best choice"?
Suppose there actually is a best word choice. The LLM doesn't know what it is but makes a guess. Maybe it's the best one, maybe it isn't. The probability that SynthID changes the best choice to a worse one is equal to the probability that it changes a worse choice to the best one.
Does the author think he is currently getting T=0 output from Claude? Is he under the impression that T=0 produces the "best" writing?
This entire article just seems so detached from the basics of how LLMs work.
No and no. I am not sure I agree with his point but I know he is not ill-informed on either of these points, because I mentioned them to him a couple of days ago.
Describing it in terms of a word-by-word choice is simpler, but writing quality is dependent on the interplay between words.
"The weather today was cold and {grey,overcast}." If the next sentence is "I miss yesterday, when it was {bright,sunny}." then the choice between "grey" and "overcast" is no longer neutral. "grey" and "bright" pair together, as do "overcast" and "sunny". Or if you disagree with my aesthetic sensibilities, consider:
The weather today was cold and {grey,gray}. The {color,colour} of the sky matched my {humorless,humourless} mood.Well, not that weird actually. He just has a hard-on against anything that comes from the EU since Apple got in trouble. If the EU said tomorrow that they want peace in the world he’d be in Fox News the next day calling for an invasion. As a former reader of Daring Fireball, it’s just sad to see.
Further he later compares Gemini to Anthropic models, saying the latter "writes better", emptily ascribing this to the synthid stuff. I think he heard that Anthropic currently has superior models, but it certainly isn't because they "write better", and if anything Opus 5 now is virtually unintelligible, before the fingerprinting.
The fingerprinting stuff sounds weird. If the EU wants it, it should be limited to the EU, and Anthropic is fully capable of doing that but clearly saw value in recognizing their own output. Is it going to destroy the quality of the output? We'll have to see, and this anti-EU piece, predicated on utter ignorance of the field, is not convincing.
I dunno, I guess that's what you should expect from Gruber but these EU-bashing articles lowered the enjoyment I got from his blog underneath the bar for me.
I think that was intended, yes.
It's still possible to use Claude to proofread - highlight grammatical, flow, structure, logic errors and make simple suggestions for you to pick and choose or adapt as you wish. No watermarking will flag your text. No flaw accusations of LLM authorship will haunt you. All will be fine.
But if you want an LLM to rewrite your text, that's (a) not proofreading, and (b) should be flagged as LLM generated ... because it is.
And if you copy-paste the answers from LLM, I think it's only fair the end result gets flagged. You're not writing it yourself.
A point of confusion for me, however: is every watermark unique? Is every algorithm for watermarking going to vary amongst models and amongst model versions? Will each model publisher keep this watermarking as a trade secret, that they alone can detect? If so, this can't scale! How do you detect "JoeBob 4.3 LLM" output? By querying every single model's watermark-detector? And if they all work by re-running the model and using tokens anew? That is extraordinarily wasteful.
If a watermark is not self-evident, or universally detectable, then it is no good. Take, for example, US currency. The security measures are published and well known. Any count-out room in retail has a big poster indicating how you can detect authentic US bills. Nobody has to accept non-US currency in the US, and so the only authenticity you need to worry about is your US bills alone. LLM watermarking has none of this in common. Currently sounding like a shitshow, if you ask me.
They will need to dodge around the EU requirements but it will probably just come down to an alternative method to watermark or a contractual assurance you won't mis-represent the source of the text.
but proof reading is a linter, not a writer. the proof reader will say "I think this is clumsy can you try x,y & z"
Then why are you using an LLM to write? They're not capable of understanding such nuance. They do pick randomly between two synonymous phrases, they do not use some super smart algorithm to pick the one that sounds the best.
This excuse doesn't hold any water at all - Occam's razor says the author is just super annoyed that his AI writing will be identifiable as AI writing.
But even if there were such a thing as a truly "best word", for some context, what are the examples here? Mango vs pineapple? Gray vs overcast? In what case is one of these better, that AI would normally infer but would suddenly be "perverted" by SynthID? Do you think your emotional state and preferences are being evaluated if they aren't explicitly in memory? And if they are there, do you think that the generator will bypass those instructions in favor of the watermark instead of placing it somewhere you won't care? I just. Genuinely don't get it. There may be words that matter in specific contexts or to you as a reader, so you should bloody well put them there.
Neither of these is "better" or "more precise"; in fact, LLMs will generally choose randomly between these candidates based on temperature, and SynthID should not distort the output of an LLM any more than the default temperature settings do already.
I agree that those are not the same sentences, but if the difference matters to you, you shouldn't be using an LLM. This difference exists at the level of what sounds better and is more evocative; to an LLM, nothing sounds like or evokes anything. They simply do not write good prose.
It is a bit of a mystery to say that “its okay to choose different tokens that we would have for watermarking bc people don’t notice” as though word choice doesn’t matter. If it doesn’t matter, doesn’t that mean that intelligence is more of a commodity than they would want it to be?
This seems like a fundamental misunderstanding of how this sort of watermarking works. (Either that, or I have a fundamental misunderstanding of how it works lol.) It doesn't change the probability distribution of the next token at all. If you were getting XYZ 48% of the time before, you're still getting XYZ 48% of the time. What's changed is where the random numbers come from. But as far as you're concerned, there's just as random as they were before, just like an encrypted message is indistinguishable from random bytes if you don't know the key.
But it doesn't! The distribution doesn't change at all. The only thing that changes is that sampling of that distribution becomes deterministic as per a precomputed seed.
I’d sacrifice a few %, easily. Maybe 10%. The models are getting smarter at such a fast rate that I’d be willing to lose a month or two of progress to help slow down the AI cheating epidemic.
It sounds like you expect this fingerprinting approach would dramatically reduce the intelligence of their models. But I’m sure anthropic has measured it. I doubt they would have rolled this out if the intelligence cost were that significant. I suspect the cost is less than 5%. I personally can’t tell any difference from before they added fingerprinting. I bet you can’t either.
I think (or I hope, anyway) that this overestimates how much impact the tweaks actually have on text.
The model has some things it "wants" to say. If it wants to tell a story about how someone reacted to dreary weather, it's going to tell approximately the same story regardless of whether the dice-roll caused it to describe the weather as "gray" or "overcast". And because "gray" and "overcast" were _already_ possibilities, the tweak from 52% -> 55% is completely lost in the noise.
But it's true that this is all based on hope. I'm confident that you could make the tweak against arbitrary prose and even a true artiste like Gruber would never be able to tell the difference. I'm less confident that there isn't some edge case somewhere that causes a tweak to be worse than 3%, especially in some narrow application where word choice _does_ matter (like law). Even then, though, laws are already written by people who are as noisy if not noisier than LLMs.
Such as?
This. I want the model I'm paying for to be "pure". I don't Anthropic or anyone else messing around with it, especially not for idiotic reasons like facillitating AI stigmatization. The "safety" nonsense is obnoxious enough.
They should train the best possible model and let the weights speak for themselves, not degrade it into some perverted form to appease people who hate AI anyway.
I honestly can't stand the way Claude writes. This watermark change just makes it scarier.
Well, akshwally...
> Interoperability. Providers must implement an interoperability solution for watermark detection such as a standardized API access method, a publicly readable signpost mechanism embedded in content, or participation in a consortium detection solution by February 2, 2027
LLMs have never been the place I've thought to expect any commitment to the craft of writing, to be fair.
Oh! If you want that, you should run your own model and set the generation temperature to 0 :) Because that's not what any commercial LLM is doing. Never has been. This is just making up a universe that doesn't exist so you can get mad about no longer being in the universe that doesn't exist.
The masking technique of using a subset of the statistical distribution for each next token isn't going to be meaningfully distinguishable from a natural language perspective. I honestly think its a very elegant way to implement watermarking. I've got no real opinions on how effective it will be to people actively trying to defeat it, but I suspect that the people who are trying to pretend that LLM text was something they wrote themselves are probably too lazy to put in the work to try and defeat it anyway.
At the point that you're generating entire volumes of text from Claude you're not really trying to be a sophisticated writer. I don't see how it's going to hurt for it to choose random related words.
Alternatively, you ask Claude to write the whole thing and proof read it yourself. In that case I'd like to know how much you'd need to change to break the watermarking, i.e. how much of a text would you need to change for it to be considered your work and not that of Claude?
Who could have seen this coming???
If this didn't have a detectable effect on the quality of the token probability calculation, the watermark wouldn't be detectable. It may be a small degradation in the quality of the output relative to the neds of many users in many situations, but it's not zero. It's literally sometimes choosing different words that it otherwise would specifically for watermarking purposes.
So, you don't own the generated text, and can't use it freely then. What if I copy paste a section, or rewrite a section of text to my liking? What if I rewrite some lines of code that contains the mark?
Security theater, and vague enough to be used as a weapon against who the government wishes.
I hope it's left off for non-EU customers.
Try running an llm like qwen 3.8 27B in Q8 locally with an intentionally very low temperature setting, it will write like a caveman crossed with a robot. You may find that an extremely literal output does not look pleasant to read for humans.
"I've been working in the media and model IP space for quite many years. What this article misses a bit is the threat model for watermarking in general. Watermarking and fingerprinting have inherently weak security guarantees -- they rely a lot on security through obscurity, weak assumed adversaries to deliver. There are clear trade offs between true positives, false positives and maintaining the quality of the media. It's true for audio-visual media, models and their outputs alike. As much as I like to take shots at poor technical choices by corps and govs, this one is unjustified. Sure, inserting glyphs is bad but biased sampling is as good as it gets in 2026."
Since the announcement, there have been many people who don't seem to fully understand what a security guarantee is, what trade offs it might involve, or how popular the type of technological solution is in general (media watermarking is ubiquitous).
And naturally, there are challenges with how you will make sense of the score in your org, e.g. you wrote an email, and it's flagged as LLM-generated because you copied two generated/edited paragraphs.
Yeah, the article might disagree with watermarking as a matter of principle, comparing it to censorship. But the methodological arguments that I have read so far have been thin in these articles.
The thing I don’t understand is why he seems to care so damned much about this subject--enough to write over 4,500 words on it!
John writes for a living. That’s his profession. He’s been writing for over 25 years now. When you’re that good at writing, and you care this much about your writing, you don’t allow an LLM to take over your job. I just can’t imagine that he’s in the market for LLMs and that literary excellence is his number one selection criterion.
So why is he so livid about it? It’s like being angry that wine is going to start coming in smaller bottles even though you don’t drink wine.
Even if he’s angry on behalf of other people, I don’t get it either. In my view, having LLMs write publishable content on your behalf is not a socially-acceptable use case, nor a professionally-acceptable one in most professions, even though people are abusing it for this purpose anyway. And besides, the models aren’t even all that good at it today. If you agree with that, then you certainly should not care if it’s using different phrasing than you otherwise might prefer if the meaning is similar enough.
I can't help but wonder if perhaps his hatred of EU technology regulation (which, admittedly, is mostly pretty dumb and is mainly just making life worse for users) is getting the better of him.
Has that ever been the case? Are they not actively tweaking their models, their fine tuning, the system prompts, the tool definitions and implementations, the guard rails, tool calls, instant responses. There are hundreds of knobs that they can change daily, or between each prompt, or even half way through a generation.
> At each decision point, they’re a little more likely to pick a word from the green list than the red list.
Wrong. There is no global red and green list. It's dependent on context and balances out on average. It won't change the result when one token is predicted overwhelmingly likely.
If Gruber can't tell a fully AI-generated article from a human-written one, perhaps he shouldn't care so much.
NB: I was told yesterday it's apparently a meme to call out Claude-generated output, but here I am, as I believe it's quite relevant to the topic at hand.
But it feels to me like you would need a hell of a lot of text to bury even a simple account ID. The nudges they are talking about are of the order of a handful of bits over several hundred words, I think?
Reminds me of printer tracking dots.
It's a good idea for many human endeavors to be able to identify AI writing. Communication, after all, is our main way of building the social fabric.
However - and crucially - good writing is still beyond the frontier of any model I've seen so far.
Watermarks for the things that truly matter may not be important at all.
Finally, as X commentators have shown, simply removing punctuation or changing a word here or adding an adverb there manually will screw up the whole process enormously.
The best will be the clever folks who retroactively apply the model distribution to fraud or other crimes to try to implicate the companies via watermark.
Gotta feel for their product, policy and legal team.
"Just flip a coin to pick a random synonym. Who cares?" - AI Labs
“Absurdly and insultingly”? Come on…
If all the providers use watermarking systems with different shifting logit weightings, and the keys are secret, you have to check every provider to see if it produced a given text.
Which is clearly ridiculous.
And if all providers collaborate and use the same weightings, or if the weightings are constant and not rotated cryptographically, a generic watermark remover becomes trivial.
That's not even getting into the legal complexities of businesses running open source models without watermarking locally.
Either they false positve on pretty much everything ever written, or the chances of catching a true positive is so low as to be useless.
Basically Cinavia for text, and that often falls over and is easy to remove even when there is megabytes of data streaming over a long period of time rather than 2 or 3 bits per wall of text, let alone what most people use claude for, when there is a strict dictionary and other tight output constraints.
Everyone who invests in AI companies wants to see the value of their investment increase.
I'd give it about 3-5 years until an AI company claims copyright over code their LLM produces. This is a crucial step in that path.
But if I craft a prompt that doesn't leave space for creativity, how can they include a watermark? e.g. "Rewrite the following text, replacing 'foo' with 'bar'."
I'm curious to see where they draw the line, and whether the watermarking really affects the (perceived) quality of results.
I was bulding a small interpreter and writing an article in ~markdown yesterday with Fable. And while it codes like a pro, it writes like a sixth grader.
Let's see how these watermarking stats hold up if/when llms start writing well.
The author has expressed a preference. Assume that there is a sequence of tokens, such that it is considered the absolute best by the author. This particular method of watermarking makes it less likely to generate that sequence, by definition.
I feel their argument would have been clearer and stronger if they had spent more time exploring the alternatives, and whether these alternatives would be just as effective. It is trivially easy to remove invisible tokens.
Like it or not, there is a public good to being able to identify AI generated content, and a small degredation in quality is tolerable in my opinion.
I don't think anybody has to worry about this issue though. Manual writing, coding, and proof reading continues to be an option. Where AI output is nothing to be ashamed of, the tools are available. For everyone else, there will be LLM providers that ignore EU law.
You can't assume that because if that was the case he'd already know what sentence to write, because that's what that means.
The notion of a best sentence requires a final cause, an end to write to. By their very nature that's not how LLMs work, so you can't 'degrade' them on that front. They can't lose a property they didn't have.
* Shows the real result from their detector instead of manipulating them, you have no way to verify * Has good enough security to prevent a key leak * Rotates keys to reduce the impact of a leak (once a key is leaked anyone can rewrite text to look more/less claude generated and it becomes useless) * Will not secretly give watermark-less access to governments or high profile corporate users * Will not use multiple secret keys to track individual users. This one might be less realistic because embedding ~32 bits of signal would probably affect quality a lot more than 1 bit.
And don't forget that the detection API will work as an oracle. If it detects your content you can send it to a different model and try again until it comes back clean.
I wonder if this is why Opus 5 keeps writing excessively long comments, even though I keep instructing it not to (both in chat, CLAUDE.md, and in its memories)
If the same red/green algorithm described in the article is applied to generated code, I cannot imagine how that does not degrade code quality (probabilistically, not at every point).
The part I agree with:
It is true that watermarking can be done by "just" swapping one PRNG for another, and it is even true that with today's LLMs, it is possible that this will not degrade the output. But it has a cost, and as things improve, that cost will matter. You are intentionally reducing the degrees of freedom in the output, and using those bits of entropy for a purpose that does not improve the quality. If you maximize your tradeoff of bits for quality, those extra bits lower the ceiling of what's possible. It's a very simple information theoretic argument, and the only plausible argument against it (that we're using those bits so inefficiently now that the new PRNG is no worse than the old) only holds in the short term.
I also agree that having TOS that forbid removing the watermarking is deeply, deeply problematic. Hell, the whole essay is well-written and persuasive, and gives good reasons why this is a poor approach.
What I disagree with, and the reason for this comment, is the entitlement.
> The idea that anything other than my needs should factor into the generation of text for me is patently offensive.
This attitude is what is patently offensive for me. This is the argument that the world is beholden to my interests. It says that worrying about negative externalities is immoral. It's another form of certain people being above the law, shareholder profit maximization über alles, might makes right, we have to do it or someone else will, "we just help people connect", {code,a gun,roofie} is just a tool.
So I agree that the watermarking has a cost. But you can't leave out that it is an attempt to reduce negative externalities of AI. Whether it's a realistic or worthwhile attempt is a whole other debate (and Gruber does a good job of debating just that in the latter part of the essay), but saying that the user's needs are the only thing that should ever be considered is reprehensible.
The question is: does this make my project "AI" or does it make it mine?
People use professional editors all the time. But they agree to give up any copyright in their edits. If I approve a change made by an editor, it becomes mine. But there is this idea that approving an AI sentence still make it AI.
We've had so many advancements in LLM samplers for improved text generation (off the top of my head: min-P, adaptive-P, XTC, DRY, p-less, Top-H, Top-n-Sigma, and so many more) but hosted LLM APIs only provide three basic knobs: temperature, top-k and top-p which are old as the mountains in LLM years at this point.
One thing that doesn't help the local LLM case is that all the popular VC backed local LLM wrappers also only support the same three ancient knobs because I suppose they're more preoccupied with their next fundraise than with keeping up with the advances in tech.
Many writers use AI to edit their own words, and this watermarking poisons the well for that use.
I think the backlash from this could be the seed that undoes their attempted 2 Trillion IPO this fall.
[1] https://doc.searls.com/2026/08/17/you-can-hear-the-squeak-of...
Also this:
"> I want any LLM I use to choose the very best, most precise words at every single decision point."
I don't think the author quite appreciates the level of randomness here.
This is more subtle then Claude changing prose.
Again - I suggest that the author would have to run a test on themselves to determine if they can actually find a difference.
And what I mean by that is that companies that are at the top tend to make anti customer decisions because they have lost the concept that pleasing customers matters as priority one.
How is this supposed to work in an actual lawsuit? Will Anthropic offer some sort of tool / (paid?) webservice to check for watermarks using that "secret key", and a judge is supposed to just believe whatever that tool's verdict is? And then it takes the EU another 20 years to understand what a silly idea this was?
The obvious conflicts here are wild.
The real argument should be watermarking itself. I don’t want my shit water marked if I ask you to just rephrase a certain part.
> "My error was believing Anthropic"
The error is rearranging part of one's life around Anthropic.
There is evidence this exists already, and it's why "I have to be honest..." and "This is the right lens, ..." keep popping up.
Probably would be cheaper too. Maybe I am missing something?
Who is even asking for this? Sounds like something some obsessive internal employees would push on the world.
And this attitude is incompatible with any models produced by frontier labs. Your needs will always be subordinate to and in service of the needs of the corporation that produced the model. And we haven't even gotten to ads yet.
Further heck: It can be said it ain't even writing.-
The premium upgrade will be "obfusicators" that further modify the text sporadically to make it look more like a human wrote it.
Students for one, will gladly pay.
It already fails. It randomly picks between close candidates. To help fool people into believing in intelligence claim, I guess.
Is Gruber only now waking up to the idea that LLM companies do not give a shit about the quality of the writing they generate? That they're disdainful of the entire concept of writing as a profession? What rock has he been under?
If you care one iota for the quality and craft of your writing, you would already recognize that any degree of AI "processing" obliterates stylistic choices. You're left with readable text, but it's fluffy, meandering, and has a cadence to the writing that screams to the reader "every second you spent on this was wasted."
No, you don't. If you wanted that, you would set the temperature parameter to 0. But that would lead to less desirable results, not better. LLMs do not set the temperature to 0; they typically set it 0.4-0.7.
Apparently superfluous descriptions, unnecessary words, and paragraph footnotes are all fine, but gumbel softmax (or whatever's going on here) isn't.
The standard procedure to do this, is to chain translations to other languages and back. The message remains, but the wording will pick up some noise. --Dec 30, 2008.
Not that it's the ideal solution. But it would be really neat.
And this is why the latest Claude models blather so much more. All for the sake of this "watermark."
I don’t see how this makes it worse.
Yeah, that about sums it up!
Somehow they'll find a way to use this for regulatory capture
How Claude's text watermarking works
A company the size of Anthropic would not voluntarily jeopardize their massive valuation if they didn’t feel the resulting output would maintain a similar level of quality as before. Is there a similar worry that their system prompt, which is injected at the start of every conversation also influences token generation in an artificial way?
If regulation will ruin Claude as a product, market forces will fill the void. There are also a ton of open weight models to choose from. It’s going to be okay.
> Also, what happens if another major global market makes it unlawful for AI to secretly watermark generated text?
The phrasing of the announcement implying that phrasing and diction don't change the meaning of text is insultingly dismissive of the whole field of literature, and I can see why people might take it as an afront, but the actual technology shouldn't have a negative impact as far as I can see. It seems to me that this one is more of a PR problem than something with real-world impact.
what if the llm should
- repeat something verbatim (important in a compaction prompt)
- there is just one correct order of tokens for a somewhat long chain (a certain sequence of control signals)
- provide a diff of 2 inputs
without punctuation or whitespace wiggle room?
how does the drifting work?
does it postpone the drifting and drift stronger later?
what if max_tokens is set to a low number?
in what way does this not affect output quality?
Total variation distance has been measured to decrease as you scale a model, and that is the primary mechanism "watermarking" as discussed in the Anthropic announcement relies on. It becomes more difficult to reliably detect text as a fixed sample count without tweaking the distribution further. Either way, it's a minor problem that will be addressed over time, compared to the issue of who can detect this without guessing or developing their own sets: providers not releasing a way to detect any such watermarks without going through them makes this entire approach hostile to the public. The EU regulation on this subject is interesting, although again most certainly not the primary driver for these practices:
"1.1.2: Signatories will ensure that AI-generated or manipulated content is marked with an imperceptible watermark, with the exception of very short text. For free-form text longer than 200 tokens, watermarking still needs to be applied, even though it may have lower reliability compared to that of watermarking very long text"
A proper, effective and useful law would have required providers to regularly release datasets to run your own verification on any text released within a fixed interval of time, presumably once out of rotation. Instead, it only talks about exposing an user interface going through their own services:
"Signatories will ensure access to their detection solution through a user interface appropriate for the audience of end-users that may eventually be exposed to the content generated or manipulated by their AI system. [...] Any restriction to the access will be limited in time until more reliable and robust detection mechanisms have emerged and have been adopted as the state of the art for detection mechanisms for the watermarking of free-form text evolves."
Most interestingly, in line with the EU's mass-surveillance program, an alternative solution to watermarking where it may not be sufficient is also suggested, although only optional for now:
"Where appropriate and taking into account potential trade-offs related to privacy and security, as well as scalability challenges and costs, Signatories may implement as an optional supplementary measure fingerprinting or logging solutions for AI-generated or manipulated content which allow for checking whether content has been generated or manipulated by their AI system. For example, direct logging may be appropriate for text content, whereas fingerprinting approaches may be preferable for audio and visual content."
Generative AI is a perversion of writing
"Important" refers to impact, "significant" to the statistical qualities of the underlying hypothesis, "substantial" to the work involved, and "notable" is a referential judgement by the speaker. The implied normalization of words and their respective meaning also marks one of the mechanisms how "slop" is typically creeping into the productions of "broad verbose interchange replicas" (it's all interchangeable, and a choice isn't really that, a choice, isn't it?).
Yeah, John. We're all OK with that.
I can't keep up with the current Chinese psycop. There should be some kind of status page like whywewantamericatofailataitoday.ai so we can keep up with it.
He had a very similar rant a couple of days ago when he somehow thought that they would use invisible characters. It’s just as useless.
https://www.youtube.com/live/2Kx9jbSMZqA?si=0QgCPBX2_KPZ0QTU...
> The difference between watermarked and un-watermarked text will not be distinguishable to readers
https://www.anthropic.com/news/claude-text-watermark
Which is to say, it does not actually meet the EU AI act requirements which require transparency to humans. Not to mention that if the detection requires access to the base models, it makes anthropic the only entity who gets the say on if a piece of text comes out of Claude. Anthropic is both the player and the referee here.
If there is one takeaway you should have from this fiasco it is that you should be wary of using tools that doesn't serve your needs and your needs only.
This is akin to adding a giant watermark on things one would made with a free product "Made with XXX". Except you're paying $200/month for it, and there's no way to disable that watermark.
I don't disagree with EU regulations, but I strongly believe the onus should be on the content publisher, not the toolmaker. If the toolmaker watermarks whatever his tool produces, it opens a giant can of worms that cannot be closed. That means anything and everything you make with this tool is no longer fully yours, it contaminates everything and makes your work traceable. Who wants that?
I was already annoyed by the fact that Claude marked everything it did on my repos under its own account (I didn't ask for any of this), but now everything is invisibly marked, even the code. Not that I care that my writing would be watermarked, since I'd rather write my stuff myself, but code? No thanks.
Meanwhile I'm running a DeepSeek V4 Flash or Pro, or a Qwen3.8, and it writes my code without a peep. Resulting repos are clean, just the way I want them. No 'Claude' account, no watermarking, nothing. I won't be looking back after having tried these new models. Whoever makes good models that don't broadcast their maker will get my business.
This watermarking will simply push people more towards Chinese models. Keep pushing in the wrong direction Anthropic. Doing this right before an IPO is a great idea.
It exhibits an undeveloped understanding of LLMs, and a righteous view that generated prose should assimilate... which should be offensive to organic intelligence.
Issues with the proprietary nature of Anthropic's watermarking aside, we will look back on this as a 'thank god' moment in the history of LLMs.
FITFY.
I have no sympathy for writers whining about what the AI is doing to 'their' writing. It's only your writing when you write it. There's any easy way to avoid this: don't fucking use it. Use you own brain.
I think they need to get their shit-together and realize this is a death warrant for the tech ( in my opinion ).
I swear, one of those days I will get into politics just to fight those two things, and the cottage industry of batshit crazy lawyers that gave birth to those things.
This also, just another precedent of anti-user, pro Authoritarian, from LLM companies.
You think someone will write Nazi-promoting AI policy like this when society is encouraged to look at their families as examples of neo-Nazi corruption? When their wives' and kids' friends spurn them while their families engage in obvious criminal activity to harm world productivity?
Critics need to be more precise.
I think this would be a good guard on websites to use it as another content protection layer.
The output quality will likely suffer as stated in the article although this can be mitigated to an extent by only enabling it on more irrelevant filler text while leaving the more functional sections untouched.
The solution using Unicode tricks amounts to malicious compliance as only the most unsophisticated users are going to fail to remove the AI watermarks when trying to pass off AI slop as their own prose.
The real solution here is not having stupid EU–tier laws in the first place.
Perhaps it's not actually irony, perhaps it is hypocrisy.
This isn't to say there aren't correct statements in the article, but its framed very strangely.
While I generally hate legal mandates to stab your customers in the back, in my opinion there is no harmless way to use AI and mandatory text watermarking is a good bare minimum. The EU probably made the right call. The entire AI space - open models included - is predicated upon worker exploitation, replacement, and deskilling; we should at least be able to know how much of our media diet has Anthropic's fingerprints on it.
A lot of hay is made over the pretraining process in which copious amounts of stolen data are trained on; but parallel to this is a huge data labeling and human feedback operation staffed almost entirely by people in third-world countries with robust English as a Second Language (ESL) programs. The thing is, AI models already watermark their text, they just happen to do so with the textual watermarks of the Indians and Nigerians that the AI companies hired to do RLHF because they were cheap. That's why certain AI models love the word "delve" so damned much. It's neocolonialism, designed specifically to do the kind of replacement the anti-immigrant idiots keep screaming their heads off about[1].
Furthermore, as we've seen with Hank Green, even non-cannibalism-adjacent AI usage is a recipe for worker deskilling and AI psychosis. The other half of the RLHF pipeline is to turn a pile of compressed text into a chatbot that feeds you a steady drip of unsourced information while praising you every time you spot one of its lies and never saying no[2]. This is a recipe for addicting your customers.
Also, this might just be because this is on daringfireball.net, but I can't help but think the author has an axe to grind against the EU because the EU mandated Apple sign third-party app stores. The fact that he's balking at Anthropic not going along with gating the watermarks to just the EU seems downstream of this - "why aren't you maximally attempting to resist the EU?"
[0] https://www.youtube.com/watch?v=YCPAIg7RUq8
[1] To be clear, upwards of none of the far-right have actually clued into the fact that AI is trained by underpaid immigrants, mainly because it doesn't fit the narratives the people running the far-right want to push. There are some AI robotics companies that are even very explicit that their robots are there primarily to launder foreign labor into rich companies and make permanent labor arbitrage.
[2] Continuing on from [1], the far-right actually really loves AI specifically because it rarely says no to even stupid ideas, even if it's also a manifestation of everything they claim to hate.
... and the opposite is also true, sometimes it will increase the probability of choosing the "best" word choice. So watermarking makes the LLM quality better then? /s
Or just em dashes? /s
> It’s unacceptable for a tool to sacrifice an iota of clarity, coherence, meaning, quality, etc. for the purpose of (watermarking)
And an example of the impact of watermarking on word choice [0]:
> The results of the study were quite [important || significant || substantial || notable]
The meaning of the sentence to changes slightly even in just this tiny example. Imagine the degradation when applied across an entire response!
I struggle to see how this could possibly be useful unless there's some sort of psy-op going on to trick people into uncritically accepting anything lacking a watermark as not being AI-generated.
A couple of days later it was up with the most comprehensive review of the available info summarised and referenced ready for a human researcher to explore.
This was only possible due to AI. It would have taken me weeks to chase it down and summarise it, so it would never have happened. Let's get off our high horse about AI writing.
The "watermark" can be trivially defeated, but may be enough to satisfy the letter of the law, and like many people here, I would argue that if you are letting Claude write for you, you've already accepted getting the literary equivalent of turd soup, so the harm is — or at least could be — fairly minuscule.
[1]: https://digital-strategy.ec.europa.eu/en/policies/code-pract...
(FWIW I have a more favorable view than most people seem to of the EU's efforts to at least try tackle problems like this — but predictably, the bureaucratic "solutions" they come up with don't work, but do make things objectively worse)
Watermarking is bad not just because of the principled stance that your tool should not be working against your own interests (the passionate argument in TFA), but specifically because it lends credence to the idea that AI detection is a valid and possible thing to do perfectly.
As technologists of course we know "oh well yes but with some confidence interval we can detect AI token bias across a large corpus of text." To JimBob in charge of publishing your paper or reviewing your PhD submission, all he knows is "anthropic says AI detection is possible so this 30% chance your paper was written by AI means you've plagiarized." Do you really think you're winning the argument with the certified, law-approved plagiarism detection machine? No, you're not, and your career is over.
It's irresponsible to develop watermarking because it is not anywhere close to a perfect science, but it will be treated like one by people with the power to ruin your lives. Even if you've never touched AI in your life, your paper is going through the "maybe it says you cheated" box, and you better hope those dice don't come up snake eyes.