Simon Willison's Blog
simonwillison.net/Quoting Ethan Mollick
The issue with GPT-5 in a nutshell is that unless you pay for model switching & know to use GPT-5 Thinking or Pro, when you ask “GPT-5” you sometimes get …
Quoting Thomas Dohmke
You know what else we noticed in the interviews? Developers rarely mentioned “time saved” as the core benefit of working in this new way with agents. They were all about …
When a Jira Ticket Can Steal Your Secrets
Zenity Labs describe a classic lethal trifecta attack, this time against Cursor, MCP, Jira and Zendesk. They also have a short video demonstrating the issue. Zendesk support emails are often …
My Lethal Trifecta talk at the Bay Area AI Security Meetup
I gave a talk on Wednesday at the Bay Area AI Security Meetup about prompt injection, the lethal trifecta and the challenges of securing systems that use MCP. It wasn’t …
Quoting @pearlmania500
I have a toddler. My biggest concern is that he doesn't eat rocks off the ground and you're talking to me about ChatGPT psychosis? Why do we even have that? …
Quoting Sam Altman
GPT-5 rollout updates: We are going to double GPT-5 rate limits for ChatGPT Plus users as we finish rollout. We will let Plus users choose to continue to use 4o. …
The surprise deprecation of GPT-4o for ChatGPT consumers
I’ve been dipping into the r/ChatGPT subreddit recently to see how people are reacting to the GPT-5 launch, and so far the vibes there are not good. This AMA thread …
Previewing GPT-5 at OpenAI's office
A couple of weeks ago I was invited to OpenAI's headquarters for a "preview event", for which I had to sign both an NDA and a video release waiver. I …
GPT-5: Key characteristics, pricing and model card
I’ve had preview access to the new GPT-5 model family for the past two weeks, and have been using GPT-5 as my daily-driver. It’s my new favorite model. It’s still …
Jules, our asynchronous coding agent, is now available for everyone
I wrote about the Jules beta back in May. Google's version of the OpenAI Codex PR-submitting hosted coding tool graduated from beta today. I'm mainly linking to this now because …
Qwen3-4B Instruct and Thinking
Yet another interesting model from Qwen - these are tiny compared to their other recent releases (just 4B parameters, 7.5GB on Hugging Face and even smaller when quantized) but with …
Quoting Artificial Analysis
gpt-oss-120b is the most intelligent American open weights model, comes behind DeepSeek R1 and Qwen3 235B in intelligence but offers efficiency benefits [...] We’re seeing the 120B beat o3-mini but …
No, AI is not Making Engineers 10x as Productive
Colton Voege on "curing your AI 10x engineer imposter syndrome". There's a lot of rhetoric out there suggesting that if you can't 10x your productivity through tricks like running a …
OpenAI's new open weight (Apache 2) models are really good
The long promised OpenAI open weight models are here, and they are very impressive. They’re available under proper open source licenses—Apache 2.0—and come in two sizes, 120B and 20B. OpenAI’s …
Claude Opus 4.1
Surprise new model from Anthropic today - Claude Opus 4.1, which they describe as "a drop-in replacement for Opus 4". My favorite thing about this model is the version number …
Quoting greyduet on r/teachers
I teach HS Science in the south. I can only speak for my district, but a few teacher work days in the wave of enthusiasm I'm seeing for AI tools …
ChatGPT agent's user-agent
I was exploring how ChatGPT agent works today. I learned some interesting things about how it exposes its identity through HTTP headers, then made a huge blunder in thinking it …
Usage charts for my LLM tool against OpenRouter
OpenRouter proxies requests to a large number of different LLMs and provides high level statistics of which models are the most popular among their users. Tools that call OpenRouter can …
Qwen-Image: Crafting with Native Text Rendering
Not content with releasing six excellent open weights LLMs in July, Qwen are kicking off August with their first ever image generation model. Qwen-Image is a 20 billion parameter MMDiT …
Quoting @himbodhisattva
for services that wrap GPT-3, is it possible to do the equivalent of sql injection? like, a prompt-injection attack? make it think it's completed the task and then get access …
I Saved a PNG Image To A Bird
Benn Jordan provides one of the all time great YouTube video titles, and it's justified. He drew an image in an audio spectrogram, played that sound to a talented starling …
Quoting Nick Turley
This week, ChatGPT is on track to reach 700M weekly active users — up from 500M at the end of March and 4× since last year.
XBai o4
Yet another open source (Apache 2.0) LLM from a Chinese AI lab. This model card claims: XBai o4 excels in complex reasoning capabilities and has now completely surpassed OpenAI-o3-mini in …
Faster inference
Two interesting examples of inference speed as a flagship feature of LLM services today. First, Cerebras announced two new monthly plans for their extremely high speed hosted model service: Cerebras …
Deep Think in the Gemini app
Google released Gemini 2.5 Deep Think this morning, exclusively to their Ultra ($250/month) subscribers: It is a variation of the model that recently achieved the gold-medal standard at this year's …
July newsletter for sponors is out
This morning I sent out the third edition of my LLM digest newsletter for my $10/month and higher sponsors on GitHub. It included the following section headers: Claude Code Model …
Quoting Logan Kilpatrick
Gemini Deep Think, our SOTA model with parallel thinking that won the IMO Gold Medal 🥇, is now available in the Gemini App for Ultra subscribers!! [...] Quick correction: this …
Reverse engineering some updates to Claude
Anthropic released two major new features for their consumer-facing Claude apps in the past couple of days. Sadly, they don’t do a very good job of updating the release notes …
Quoting Christina Wodtke
The old timers who built the early web are coding with AI like it's 1995. Think about it: They gave blockchain the sniff test and walked away. Ignored crypto (and …
More model releases on 31st July
Here are a few more model releases from today, to round out a very busy July: Cohere released Command A Vision, their first multi-modal (image input) LLM. Like their others …
Trying out Qwen3 Coder Flash using LM Studio and Open WebUI and LLM
Qwen just released their sixth model(!) for this July called Qwen3-Coder-30B-A3B-Instruct—listed as Qwen3-Coder-Flash in their chat.qwen.ai interface. It’s 30.5B total parameters with 3.3B active at any one time. This means …
Ollama's new app
Ollama has been one of my favorite ways to run local models for a while - it makes it really easy to download models, and it's smart about keeping them …
Quoting Steve Krouse
When you vibe code, you are incurring tech debt as fast as the LLM can spit it out. Which is why vibe coding is perfect for prototypes and throwaway projects: …
The best available open weight LLMs now come from China
Something that has become undeniable this month is that the best available open weight models now come from the Chinese AI labs. I continue to have a lot of love …
Qwen3-30B-A3B-Thinking-2507
Yesterday was Qwen3-30B-A3B-Instruct-2507. Qwen are clearly committed to their new split between reasoning and non-reasoning models (a reversal from Qwen 3 in April), because today they released the new reasoning …
OpenAI: Introducing study mode
New ChatGPT feature, which can be triggered by typing /study or by visiting chatgpt.com/studymode. OpenAI say: Under the hood, study mode is powered by custom system instructions we’ve written in …
Qwen/Qwen3-30B-A3B-Instruct-2507
New model update from Qwen, improving on their previous Qwen3-30B-A3B release from late April. In their tweet they said: Smarter, faster, and local deployment-friendly. ✨ Key Enhancements: ✅ Enhanced reasoning, …
Quoting Nilay Patel
Our plan is to build direct traffic to our site. and newsletters just one kind of direct traffic in the end. I don’t intend to ever rely on someone else’s …
Quoting Anthropic
We’re rolling out new weekly rate limits for Claude Pro and Max in late August. We estimate they’ll apply to less than 5% of subscribers based on current usage. [...] …
GLM-4.5: Reasoning, Coding, and Agentic Abililties
Another day, another significant new open weight model release from a Chinese frontier AI lab. This time it's Z.ai - who rebranded (at least in English) from Zhipu AI a …
Enough AI copilots! We need AI HUDs
Geoffrey Litt compares Copilots - AI assistants that you engage in dialog with and work with you to complete a task - with HUDs, Head-Up Displays, which enhance your working …
Official statement from Tea on their data leak
Tea is a dating safety app for women that lets them share notes about potential dates. The other day it was subject to a truly egregious data leak caused by …
Qwen3-235B-A22B-Thinking-2507
The third Qwen model release week, following Qwen3-235B-A22B-Instruct-2507 on Monday 21st and Qwen3-Coder-480B-A35B-Instruct on Tuesday 22nd. Those two were both non-reasoning models - a change from the previous models in …
Using GitHub Spark to reverse engineer GitHub Spark
GitHub Spark was released in public preview yesterday. It’s GitHub’s implementation of the prompt-to-app pattern also seen in products like Claude Artifacts, Lovable, Vercel v0, Val Town Townie and Fly.io’s …
Quoting Recurse Center
[...] You learn best and most effectively when you are learning something that you care about. Your work becomes meaningful and something you can be proud of only when you …
Instagram Reel: Veo 3 paid preview
@googlefordevs on Instagram published this reel featuring Christina Warren with prompting tips for the new Veo 3 paid preview (mp4 copy here). (Christine checked first if I minded them using …
TimeScope: How Long Can Your Video Large Multimodal Model Go?
New open source benchmark for evaluating vision LLMs on how well they handle long videos: TimeScope probes the limits of long-video capabilities by inserting several short (~5-10 second) video clips---our …
1KB JS Numbers Station
Terence Eden built a neat and weird 1023 byte JavaScript demo that simulates a numbers station using the browser SpeechSynthesisUtterance, which I hadn't realized is supported by every modern browser …
Quoting Dave White
like, one day you discover you can talk to dogs. it's fun and interesting so you do it more, learning the intricacies of their language and their deepest customs. you …
Quoting ICML 2025
Submitting a paper with a "hidden" prompt is scientific misconduct if that prompt is intended to obtain a favorable review from an LLM. The inclusion of such a prompt is …
Qwen3-Coder: Agentic Coding in the World
It turns out that as I was typing up my notes on Qwen3-235B-A22B-Instruct-2507 the Qwen team were unleashing something much bigger: Today, we’re announcing Qwen3-Coder, our most agentic code model …
Qwen/Qwen3-235B-A22B-Instruct-2507
Significant new model release from Qwen, published yesterday without much fanfare. This is a follow-up to their April release of the full Qwen 3 model family, which included a Qwen3-235B-A22B …
Subliminal Learning: Language Models Transmit Behavioral Traits via Hidden Signals in Data
This new alignment paper from Anthropic wins my prize for best illustrative figure so far this year: The researchers found that fine-tuning a model on data generated by another model …
Our contribution to a global environmental standard for AI
Mistral have released environmental impact numbers for their largest model, Mistral Large 2, in more detail than I have seen from any of the other large AI labs. The methodology …
Gemini 2.5 Flash-Lite is now stable and generally available
The last remaining member of the Gemini 2.5 trio joins Pro and Flash in General Availability today. Gemini 2.5 Flash-Lite is the cheapest of the 2.5 family, at $0.10/million input …
Textual v4.0.0: The Streaming Release
Will McGugan may no longer be running a commercial company around Textual, but that hasn't stopped his progress on the open source project. He recently released v4 of his Python …
tidwall/pogocache
New project from Josh Baker, author of the excellent tg C geospatial libarry (covered previously) and various other interesting projects: Pogocache is fast caching software built from scratch with a …
Advanced version of Gemini with Deep Think officially achieves gold-medal standard at the International Mathematical Olympiad
OpenAI beat them to the punch in terms of publicity by publishing their results on Saturday, but a team from Google Gemini achieved an equally impressive result on this year's …
Quoting Daniel Litt
An AI tool that gets gold on the IMO is obviously immensely impressive. Does it mean math is “solved”? Is an AI-generated proof of the Riemann hypothesis clearly on the …
Coding with LLMs in the summer of 2025 (an update)
Salvatore Sanfilippo describes his current AI-assisted development workflow. He's all-in on LLMs for code review, exploratory prototyping, pair-design and writing "part of the code under your clear specifications", but warns …
Quoting Armin Ronacher
Every day someone becomes a programmer because they figured out how to make ChatGPT build something. Lucky for us: in many of those cases the AI picks Python. We should …
Quoting Tim Sweeney
There’s a bigger opportunity in computer science and programming (academically conveyed or self-taught) now than ever before, by far, in my opinion. The move to AI is like replacing shovels …
OpenAI's gold medal performance on the International Math Olympiad
OpenAI research scientist Alexander Wei: I’m excited to share that our latest @OpenAI experimental reasoning LLM has achieved a longstanding grand challenge in AI: gold medal-level performance on the world’s …
New tags
A few months I added a tool to my blog for bulk-applying tags to old content. It works as an extension to my existing search interface, letting me run searches …
Quoting Steve Yegge
So one of my favorite things to do is give my coding agents more and more permissions and freedom, just to see how far I can push their productivity without …
Quoting Paul Kedrosky
One analyst recently speculated (via Ed Conard) that, based on Nvidia's latest datacenter sales figures, AI capex may be ~2% of US GDP in 2025, given a standard multiplier. [...] …
How to run an LLM on your laptop
I talked to Grace Huckins for this piece from MIT Technology Review on running local models. Apparently she enjoyed my dystopian backup plan! Simon Willison has a plan for the …
Voxtral
Mistral released their first audio-input models yesterday: Voxtral Small and Voxtral Mini. These state‑of‑the‑art speech understanding models are available in two sizes—a 24B variant for production-scale applications and a 3B …
common-pile/caselaw_access_project
Enormous openly licensed (I believe this is almost all public domain) training dataset of US legal cases: This dataset contains 6.7 million cases from the Caselaw Access Project and Court …
Reflections on OpenAI
Calvin French-Owen spent just over a year working at OpenAI, during which time the organization grew from 1,000 to 3,000 people and Calvin found himself in "the top 30% by …
xAI: "We spotted a couple of issues with Grok 4 recently that we immediately investigated & mitigated"
They continue: One was that if you ask it "What is your surname?" it doesn't have one so it searches the internet leading to undesirable results, such as when its …
Application development without programmers
This book by James Martin, published in 1982, includes the following in the preface: Applications development did not change much for 20 years, but now a new wave is crashing …
ccusage
Claude Code logs detailed usage information to the ~/.claude/ directory. ccusage is a neat little Node.js tool which reads that information and shows you a readable summary of your usage …
Measuring the Impact of Early-2025 AI on Experienced Open-Source Developer Productivity
METR - for Model Evaluation & Threat Research - are a non-profit research institute founded by Beth Barnes, a former alignment researcher at OpenAI (see Wikipedia). They've previously contributed to …
Grok 4 Heavy won't reveal its system prompt
Grok 4 Heavy is the "think much harder" version of Grok 4 that's currenly only available on their $300/month plan. Jeremy Howard relays a report from a Grok 4 Heavy …
Quoting @grok
On the morning of July 8, 2025, we observed undesired responses and immediately began investigating. To identify the specific language in the instructions causing the undesired behavior, we conducted multiple …
Musk’s latest Grok chatbot searches for billionaire mogul’s views before answering questions
I got quoted a couple of times in this story about Grok searching for tweets from:elonmusk by Matt O’Brien for the Associated Press. “It’s extraordinary,” said Simon Willison, an independent …
moonshotai/Kimi-K2-Instruct
Colossal new open weights model release today from Moonshot AI, a two year old Chinese AI lab with a name inspired by Pink Floyd’s album The Dark Side of the …
Quoting Django’s security policies
Following the widespread availability of large language models (LLMs), the Django Security Team has received a growing number of security reports generated partially or entirely using such tools. Many of …
Generationship: Ep. #39, Simon Willison
I recorded this podcast episode with Rachel Chalmers a few weeks ago. We talked about the resurgence of blogging, the legacy of Google Reader, learning in public, LLMs as weirdly …
Grok: searching X for "from:elonmusk (Israel OR Palestine OR Hamas OR Gaza)"
If you ask the new Grok 4 for opinions on controversial questions, it will sometimes run a search to find out Elon Musk’s stance before providing you with an answer. …
Grok 4
Released last night, Grok 4 is now available via both API and a paid subscription for end-users. Key characteristics: image and text input, text output. 256,000 context length (twice that …