Shared some notes on Python 3.15, using it with uv, and features from Python 3.11 I'm excited to use now that 3.10 is no longer the minimum ...

What's the best open weight Mixture-of-Experts LLM for coding that fits in less than 60GB of RAM? I think MoE might be necessary to get rea...

I built a new feature for my blog entirely by voice with Codex Desktop, while I was cooking dinner https://simonwillison.net/2026/Oct/9/buil...

This "Super Intelligence" thing is just so, so, so stupid I can't even

New open source cross-platform (Windows, macOS, Linux) sandboxing library from Microsoft - looks very promising, uses processcontainer/bubbl...

Pelicans and a bunch of notes on the pricing of the new Claude Haiku 5.5 https://simonwillison.net/2026/Oct/7/claude-haiku-5-5/

I released an LLM plugin for sending prompts to OpenAI's new Jev-clone decision model that's based on GPT-6 Luna https://simonwillison.net/2...

Anyone know when the models started being able to compose competent music? I had Opus 5.5 "write some computer game music for me" and the re...

I re-ran an experiment @colin_fraser ran against GPT-4o a while back to see how good it was at adding long numbers, only this time I tried Q...

Just published this post about how we’re going to need default hard budget caps on pretty much everything https://simonwillison.net/2026/Oct...

Now that we've had a few days with it, how are people differentiating between Dot and regular ChatGPT? I'm having trouble deciding when I s...

I'm at OpenAI's DevDay event in San Francisco today - as I have for the past three DevDay events, I'm running a live blog where I'll be post...

The most important thing about Sonnet 5.5 is that it's now the model that powers the free tier on https://claude.ai - so all of this stuff c...

I've published detailed notes and an annotated transcript to accompany the video of the keynote I gave at @WeAreDevs World Congress North Am...

I included a few references to this year's record-breaking Kākāpō breeding season in a talk I gave yesterday, and since Claude Opus 5.5 is s...

"The last year in the technology industry has felt like 100 years all happening at once. Our industry is destabilized in a way nobody’s expe...

I'm on stage for the keynote in ten minutes time! https://twitter.com/wearedevs/status/2103276087358722294

The more time I spend working with coding agents, the more convinced I am that they make software engineering even harder We can do amazing...

I just had a voice conversation with the Datasette backup of my blog via datasette-mcp, which you can now talk to using the ChatGPT iPhone a...

The new Gemini 3.8 TTS models are super-cheap and can generate conversations between multiple voices (from 2,000+, or you can clone your own...