251–260 of 819 posts
I had access to a preview over the weekend, I published some notes here: https://simonwillison.net/2025/Sep/29/claude-sonnet-4-5/ It's very good - I think probably a tiny bit better than GPT-5-Codex, based on vibes more than a comprehensive comparison (there are plenty of benchmarks out there that attempt to be more methodical than vibes). It particularly shines when you try it on https://claude.ai/ using its brand n…
> I told it to Give me a zip file of everything you have done so far—you can explore the contents of the file it made me in this Gist. For those who don't have time to dig into the gist, did it work and do a good job? I assume yes to at least nominally working or you would have mentioned that, but any other thoughts on the solution it produced?
I really hope benchmarking improves soon to monitor the model in the weeks following the announcement. It really seems like these companies introduce a new "buffed" model and then slowly nerf the intelligence through optimizations. If we saw task performance week 1 vs week 8 on benchmarks, this would at least give us more insight into the loop here. In an environment lacking true progress a company could surely "show…
I do wonder about this. I just don't know if it real or in our heads
Earlier quoted context omitted.
> I'm infinity times more productive, as I just wouldn't even start projects without the LLM to sidestep my ADHD. 1 is not infinitely greater than 0.
It... literally is? Or otherwise, can you share what you think the ratio is?
It is not a ratio, it is a proportion.
It's pretty good! I wrote about a few other use cases on my blog[2]
1: https://systeminit.com 2: https://keeb.dev/2025/09/29/claude-sonnet-4.5-system-initiat...
I had access to a preview over the weekend, I published some notes here: https://simonwillison.net/2025/Sep/29/claude-sonnet-4-5/ It's very good - I think probably a tiny bit better than GPT-5-Codex, based on vibes more than a comprehensive comparison (there are plenty of benchmarks out there that attempt to be more methodical than vibes). It particularly shines when you try it on https://claude.ai/ using its brand n…
Why did you have access to a preview?
I won't accept preview access if it comes with any conditions at all about what I can say about the model once the embargo has lifted.
Earlier quoted context omitted.
GP is right, though. Many programming communities, including (in some threads, but not all) HN, have become ridiculous anti-AI bubbles - what's the point of trying to have a discussion if you're going to get systematically shut down by people whose entire premise is that they don't use it? It's like trying to explain color to the blind. What "discussion" do you want to have? Another round of "LLMs are terrible at emb…
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Now you may read that as .. checks notes "star trek post scarcity singularity", but forgive me, I didn't.
I have a fairly large web application with ~200k LoC.
Gave the same prompt to Sonnet 4.5 (Claude Code) and GPT-5-Codex (Codex CLI).
"implement a fuzzy search for conversations and reports either when selecting "Go to Conversation" or "Go to Report" and typing the title or when the user types in the title in the main input field, and none of the standard elements match, a search starts with a 2s delay"
Sonnet 4.5 went really fast at ~3min. But what it built was broken and superficial. The code did not even manage to reuse already existing auth and started re-building auth server-side instead of looking how other API endpoints do it. Even re-prompting and telling it how it went wrong did not help much. No tests were written (despite the project rules requiring it).
GPT-5-Codex needed MUCH longer ~20min. Changes made were much more profound, but it implemented proper error handling, lots of edge cases and wrote tests without me prompting it to do so (project rules already require it). API calls ran smoothly. The entire feature worked perfectly.
My conclusion is clear: GPT-5-Codex is the clear winner, not even close.
I will take the 20mins every single time, knowing the work that has been done feels like work done by a senior dev.
The 3mins surprised me a lot and I was hoping to see great results in such a short period of time. But of course, a quick & dirty, buggy implementation with no tests is not what I wanted.
I'm really interested in the progress on computer use. These are the benchmarks to watch if you want to forecast economic disruption, IMO. Mastery of computer use takes us out of the paradigm of task-specific integrations with AI to a more generic interface that's way more scalable.
I had access to a preview over the weekend, I published some notes here: https://simonwillison.net/2025/Sep/29/claude-sonnet-4-5/ It's very good - I think probably a tiny bit better than GPT-5-Codex, based on vibes more than a comprehensive comparison (there are plenty of benchmarks out there that attempt to be more methodical than vibes). It particularly shines when you try it on https://claude.ai/ using its brand n…
Why did you have access to a preview?