Claude 4 System Card
simonwillison.net
Claude 4 System Card
1–10 of 264 posts
Re: Claude 4 System Card
#2https://www.lakera.ai/blog/claude-4-sonnet-a-new-standard-fo...
These LLMs still fall short on a bunch of pretty simple tasks. Attackers can get Claude 4 to deny legitimate requests easily by manipulating third party data sources for example.
Re: Claude 4 System Card
#3https://www.lakera.ai/blog/claude-4-sonnet-a-new-standard-fo... These LLMs still fall short on a bunch of pretty simple tasks. Attackers can get Claude 4 to deny legitimate requests easily by manipulating third party data sources for example.
They gave a bullet point in that intro which I disagree with: "The only way to make GenAI applications secure is through vulnerability scanning and guardrail protections."
I still don't see guardrails and scanning as effective ways to prevent malicious attackers. They can't get to 100% effective, at which point a sufficiently motivated attacker is going to find a way through.
I'm hoping someone implements a version of the CaMeL paper - that solution seems much more credible to me. https://simonwillison.net/2025/Apr/11/camel/
Re: Claude 4 System Card
#4https://www.lakera.ai/blog/claude-4-sonnet-a-new-standard-fo... These LLMs still fall short on a bunch of pretty simple tasks. Attackers can get Claude 4 to deny legitimate requests easily by manipulating third party data sources for example.
They gave a bullet point in that intro which I disagree with: "The only way to make GenAI applications secure is through vulnerability scanning and guardrail protections." I still don't see guardrails and scanning as effective ways to prevent malicious attackers. They can't get to 100% effective, at which point a sufficiently motivated attacker is going to find a way through. I'm hoping someone implements a version o…
Agreed on CaMeL as a promising direction forward. Guardrails may not get 100% of the way but are key for defense in depth, even approached like CaMeL currently fall short for text to text attacks, or more e2e agentic systems.
Re: Claude 4 System Card
#5Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment?
The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt.
What are folks’ theories on the version increment? Is the architecture significantly different (not talking about adding more experts to the MoE or fine tuning on 3.7’s worst failures. I consider those minor increments rather than major).
One way that it could be different is if they varied several core hyperparameters to make this a wider/deeper system but trained it on the same data or initialized inner layers to their exact 3.7 weights. And then this would “kick off” the 4 series by allowing them to continue scaling within the 4 series model architecture.
Re: Claude 4 System Card
#6Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment? The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt. What are folks’ theories on the version increment? Is the architecture sig…
> to justify the full version increment
I feel like a company doesn’t have to justify a version increment. They should justify price increases.
If you get hyped and have expectations for a number then I’m comfortable saying that’s on you.
Re: Claude 4 System Card
#7Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment? The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt. What are folks’ theories on the version increment? Is the architecture sig…
> to justify the full version increment I feel like a company doesn’t have to justify a version increment. They should justify price increases. If you get hyped and have expectations for a number then I’m comfortable saying that’s on you.
That’s an odd way to defend the decision. “It doesn’t make sense because nothing has to make sense”. Sure, but it would be more interesting if you had any evidence that they decided to simply do away with any logical premise for the 4 moniker.
Re: Claude 4 System Card
#8Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment? The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt. What are folks’ theories on the version increment? Is the architecture sig…
Just anecdotal experience, but this model seems more eager to write tests, create test scripts and call various tools than the previous one. Of course this results in more roundtrips and overall more tokens used and more money for the provider.
I had to stop the model going crazy with unnecessary tests several times, which isn't something I had to do previously. Can be fixed with a prompt but can't help but wonder if some providers explicitly train their models to be overly verbose.
Re: Claude 4 System Card
#9Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment? The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt. What are folks’ theories on the version increment? Is the architecture sig…
Just anecdotal experience, but this model seems more eager to write tests, create test scripts and call various tools than the previous one. Of course this results in more roundtrips and overall more tokens used and more money for the provider. I had to stop the model going crazy with unnecessary tests several times, which isn't something I had to do previously. Can be fixed with a prompt but can't help but wonder if…
Eagerness to tool call is an interesting observation. Certainly an MCP ecosystem would require a tool biased model.
However, after having pretty deep experience with writing book (or novella) length system prompts, what you mentioned doesn’t feel like a “regime change” in model behavior. I.e it could do those things because its been asked to do those things.
The numbers presented in this paper were almost certainly after extensive system prompt ablations, and the fact that we’re within a tenth of a percent difference in some cases indicates less fundamental changes.
Re: Claude 4 System Card
#10Given the cited stats here and elsewhere as well as in everyday experience, does anyone else feel that this model isn’t significantly different, at least to justify the full version increment? The one statistic mentioned in this overview where they observed a 67% drop seems like it could easily be reduced simply by editing 3.7’s system prompt. What are folks’ theories on the version increment? Is the architecture sig…
[deleted]