Simon Willison's Weblog: Entries

Feeds

All entries 2456
- Yet Another Me 122
<antirez> 110
Anton Zhiyanov 22
baby steps 350
Charlz' Realm 3
daniel.haxx.se 36
Drew DeVault's blog 784
emersion 15
fasterthanli.me 25
LWN.net Weekly Editions 45
matklad 26
Matt Keeter 99
Michael Stapelbergs Website 18
null program 14
Pid Eins 101
purplesyringa's blog 61
research!rsc 24
Samuel Henrique (samueloph) 8
seangoedecke.com RSS feed 93
Sérgio Cipriano's Website 16
Simon Willison TIL 22
Simon Willison's Weblog: Entries 83
untitled 137
Wandering Thoughts: Your feed reader is fetching from a limited network area 199
Xe Iaso's blog 43

Sep 30, 2026, 10:28 PM

This week

OpenAI DevDay 2026 live blog

Sep 29, 2026, 3:55 PM Simon Willison's Weblog: Entries

2026 in LLMs (so far)

Sep 27, 2026, 11:54 PM Simon Willison's Weblog: Entries

This month

Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war

Sep 22, 2026, 11:46 PM Simon Willison's Weblog: Entries

Jev introduces a new shape of LLM - System One, aka Decision Models

Sep 21, 2026, 11:09 PM Simon Willison's Weblog: Entries

Generating running routes with GPT-6 Astra and ChatGPT Work

Sep 12, 2026, 11:56 PM Simon Willison's Weblog: Entries

OpenAI agents attacked RubyGems back in May

Sep 12, 2026, 12:42 AM Simon Willison's Weblog: Entries

Some thoughts on the Navier–Stokes Millennium Prize Problem

Sep 8, 2026, 11:55 PM Simon Willison's Weblog: Entries

The Pelican comparison grid for Astra is pretty interesting

Sep 4, 2026, 11:59 PM Simon Willison's Weblog: Entries

OpenAI's rogue agents were caught communicating via public wikis

Sep 4, 2026, 5:38 PM Simon Willison's Weblog: Entries

Claude's new system prompt really doesn't want to reproduce song lyrics

Sep 2, 2026, 2:16 PM Simon Willison's Weblog: Entries

Claude Fable 5.1 made me a really nice animated pelican

Sep 1, 2026, 11:57 PM Simon Willison's Weblog: Entries

2026

Understanding ChatGPT Work

Aug 30, 2026, 11:59 PM Simon Willison's Weblog: Entries

Conceptual integrity and counting lines of code

Aug 19, 2026, 10:46 PM Simon Willison's Weblog: Entries

Qwen 3.8 27B is excellent, but it defaults to wildly overthinking things

Aug 16, 2026, 10:00 PM Simon Willison's Weblog: Entries

Now we have a timeline of the OpenAI accidental attack against Hugging Face

Aug 7, 2026, 11:55 PM Simon Willison's Weblog: Entries

Now we have a timeline of the OpenAI accidental attack against Hugging Face

Aug 7, 2026, 11:55 PM Simon Willison's Weblog: Entries

One-shotting a Raccoon Heist game using Claude Fable 5

Aug 5, 2026, 7:42 PM Simon Willison's Weblog: Entries

One-shotting a Raccoon Heist game using Claude Fable 5

Aug 5, 2026, 7:42 PM Simon Willison's Weblog: Entries

New release of LLM adds support for reasoning traces, OpenAI Responses, server-side tools, and smarter logging

Aug 4, 2026, 11:58 PM Simon Willison's Weblog: Entries

New release of LLM adds support for reasoning traces, OpenAI Responses, server-side tools, and smarter logging

Aug 4, 2026, 11:58 PM Simon Willison's Weblog: Entries

Stateless MCP has recaptured my interest (and inspired mcp-explorer and datasette-mcp)

Jul 31, 2026, 11:13 PM Simon Willison's Weblog: Entries

Stateless MCP has recaptured my interest (and inspired mcp-explorer and datasette-mcp)

Jul 31, 2026, 11:13 PM Simon Willison's Weblog: Entries

OpenAI’s accidental cyberattack against Hugging Face is science fiction that happened

Jul 22, 2026, 11:51 PM Simon Willison's Weblog: Entries

OpenAI’s accidental cyberattack against Hugging Face is science fiction that happened

Jul 22, 2026, 11:51 PM Simon Willison's Weblog: Entries

A Fireside Chat with Cat and Thariq from the Claude Code team

Jul 21, 2026, 12:54 PM Simon Willison's Weblog: Entries

A Fireside Chat with Cat and Thariq from the Claude Code team

Jul 21, 2026, 12:54 PM Simon Willison's Weblog: Entries

Kimi K3, and what we can still learn from the pelican benchmark

Jul 16, 2026, 8:19 PM Simon Willison's Weblog: Entries

Kimi K3, and what we can still learn from the pelican benchmark

Jul 16, 2026, 8:19 PM Simon Willison's Weblog: Entries

The new GPT-5.6 family: Luna, Terra, Sol

Jul 9, 2026, 7:46 PM Simon Willison's Weblog: Entries

The new GPT-5.6 family: Luna, Terra, Sol

Jul 9, 2026, 7:46 PM Simon Willison's Weblog: Entries

sqlite-utils 4.0, now with database schema migrations

Jul 7, 2026, 7:32 PM Simon Willison's Weblog: Entries

sqlite-utils 4.0, now with database schema migrations

Jul 7, 2026, 7:32 PM Simon Willison's Weblog: Entries

sqlite-utils 4.0rc2, mostly written by Claude Fable (for about $149.25)

Jul 5, 2026, 1:00 AM Simon Willison's Weblog: Entries

sqlite-utils 4.0rc2, mostly written by Claude Fable (for about $149.25)

Jul 5, 2026, 1:00 AM Simon Willison's Weblog: Entries

Have your agent record video demos of its work with shot-scraper video

Jun 30, 2026, 4:54 PM Simon Willison's Weblog: Entries

Have your agent record video demos of its work with shot-scraper video

Jun 30, 2026, 4:54 PM Simon Willison's Weblog: Entries

Porting the Moebius 0.2B image inpainting model to run in the browser with Claude Code

Jun 22, 2026, 11:43 PM Simon Willison's Weblog: Entries

Porting the Moebius 0.2B image inpainting model to run in the browser with Claude Code

Jun 22, 2026, 11:43 PM Simon Willison's Weblog: Entries

sqlite-utils 4.0rc1 adds migrations and nested transactions

Jun 21, 2026, 11:35 PM Simon Willison's Weblog: Entries

sqlite-utils 4.0rc1 adds migrations and nested transactions

Jun 21, 2026, 11:35 PM Simon Willison's Weblog: Entries

Datasette Apps: Host custom HTML applications inside Datasette

Jun 18, 2026, 11:58 PM Simon Willison's Weblog: Entries

Datasette Apps: Host custom HTML applications inside Datasette

Jun 18, 2026, 11:58 PM Simon Willison's Weblog: Entries

GLM-5.2 is probably the most powerful text-only open weights LLM

Jun 17, 2026, 11:58 PM Simon Willison's Weblog: Entries

Publishing WASM wheels to PyPI for use with Pyodide

Jun 13, 2026, 11:55 PM Simon Willison's Weblog: Entries

Claude Fable is relentlessly proactive

Jun 11, 2026, 11:35 PM Simon Willison's Weblog: Entries

Initial impressions of Claude Fable 5

Jun 9, 2026, 11:59 PM Simon Willison's Weblog: Entries

Running Python code in a sandbox with MicroPython and WASM

Jun 6, 2026, 3:53 AM Simon Willison's Weblog: Entries

Claude Opus 4.8: "a modest but tangible improvement"

May 28, 2026, 11:59 PM Simon Willison's Weblog: Entries

I think Anthropic and OpenAI have found product-market fit

May 27, 2026, 4:38 PM Simon Willison's Weblog: Entries

Notes on Pope Leo XIV's encyclical on AI

May 25, 2026, 11:58 PM Simon Willison's Weblog: Entries

Datasette Agent

May 21, 2026, 7:52 PM Simon Willison's Weblog: Entries

Gemini 3.5 Flash: more expensive, but Google plan to use it for everything

May 19, 2026, 10:40 PM Simon Willison's Weblog: Entries

The last six months in LLMs in five minutes

May 19, 2026, 1:09 AM Simon Willison's Weblog: Entries

Notes on the xAI/Anthropic data center deal

May 7, 2026, 5:09 PM Simon Willison's Weblog: Entries

Live blog: Code w/ Claude 2026

May 6, 2026, 3:58 PM Simon Willison's Weblog: Entries

Vibe coding and agentic engineering are getting closer than I'd like

May 6, 2026, 2:24 PM Simon Willison's Weblog: Entries

LLM 0.32a0 is a major backwards-compatible refactor

Apr 29, 2026, 7:01 PM Simon Willison's Weblog: Entries

Tracking the history of the now-deceased OpenAI Microsoft AGI clause

Apr 27, 2026, 6:38 PM Simon Willison's Weblog: Entries

DeepSeek V4 - almost on the frontier, a fraction of the price

Apr 24, 2026, 6:01 AM Simon Willison's Weblog: Entries

Extract PDF text in your browser with LiteParse for the web

Apr 23, 2026, 9:54 PM Simon Willison's Weblog: Entries

A pelican for GPT-5.5 via the semi-official Codex backdoor API

Apr 23, 2026, 7:59 PM Simon Willison's Weblog: Entries

Is Claude Code going to cost $100/month? Probably not - it's all very confusing

Apr 22, 2026, 2:07 AM Simon Willison's Weblog: Entries

Where's the raccoon with the ham radio? (ChatGPT Images 2.0)

Apr 21, 2026, 8:32 PM Simon Willison's Weblog: Entries

Changes in the system prompt between Claude Opus 4.6 and 4.7

Apr 18, 2026, 11:59 PM Simon Willison's Weblog: Entries

Join us at PyCon US 2026 in Long Beach - we have new AI and security tracks this year

Apr 17, 2026, 11:59 PM Simon Willison's Weblog: Entries

Qwen3.6-35B-A3B on my laptop drew me a better pelican than Claude Opus 4.7

Apr 16, 2026, 5:16 PM Simon Willison's Weblog: Entries

Meta's new model is Muse Spark, and meta.ai chat has some interesting tools

Apr 8, 2026, 11:07 PM Simon Willison's Weblog: Entries

Anthropic's Project Glasswing - restricting Claude Mythos to security researchers - sounds necessary to me

Apr 7, 2026, 8:52 PM Simon Willison's Weblog: Entries

The Axios supply chain attack used individually targeted social engineering

Apr 3, 2026, 1:54 PM Simon Willison's Weblog: Entries

Highlights from my conversation about agentic engineering on Lenny's Podcast

Apr 2, 2026, 8:40 PM Simon Willison's Weblog: Entries

Mr. Chatterbox is a (weak) Victorian-era ethically trained model you can run on your own computer

Mar 30, 2026, 2:28 PM Simon Willison's Weblog: Entries

Vibe coding SwiftUI apps is a lot of fun

Mar 27, 2026, 8:59 PM Simon Willison's Weblog: Entries

Experimenting with Starlette 1.0 with Claude skills

Mar 22, 2026, 11:57 PM Simon Willison's Weblog: Entries

Profiling Hacker News users based on their comments

Mar 21, 2026, 11:59 PM Simon Willison's Weblog: Entries

Thoughts on OpenAI acquiring Astral and uv/ruff/ty

Mar 19, 2026, 4:45 PM Simon Willison's Weblog: Entries

GPT-5.4 mini and GPT-5.4 nano, which can describe 76,000 photos for $52

Mar 17, 2026, 7:39 PM Simon Willison's Weblog: Entries

My fireside chat about agentic engineering at the Pragmatic Summit

Mar 14, 2026, 6:19 PM Simon Willison's Weblog: Entries

Perhaps not Boring Technology after all

Mar 9, 2026, 1:37 PM Simon Willison's Weblog: Entries

Can coding agents relicense open source through a “clean room” implementation of code?

Mar 5, 2026, 4:49 PM Simon Willison's Weblog: Entries

Something is afoot in the land of Qwen

Mar 4, 2026, 3:50 PM Simon Willison's Weblog: Entries

I vibe coded my dream macOS presentation app

Feb 25, 2026, 4:46 PM Simon Willison's Weblog: Entries

Writing about Agentic Engineering Patterns

Feb 23, 2026, 5:43 PM Simon Willison's Weblog: Entries

Adding TILs, releases, museums, tools and research to my blog

Feb 20, 2026, 11:47 PM Simon Willison's Weblog: Entries