Simon Willison — Independent developer and writer documenting practical experiments, tools, and deep analysis around large language models, generative AI, web development, security, and emerging programming workflows through detailed posts and daily TILs.
170 articles from this blog
Anthropic's run-rate revenue hits $47 billion, as disclosed in their Series H announcement, showing rapid growth.
Anthropic releases Claude Opus 4.8 with modest improvements, emphasizing honesty and reduced hallucinations in AI models.
A tool to render markdown with live preview, supporting tables, code blocks, and interactive SVG from URLs or pasted content.
SQLite adds AGENTS.md file clarifying no acceptance of AI-generated code, while splitting AI bug reports into a separate forum.
Analysis of Anthropic and OpenAI achieving product-market fit through enterprise API pricing and rising AI usage costs.
A humorous anecdote about an AI-generated image of a horse riding an astronaut on a pelican on a bicycle, with a self-added sign.
A quote from Romain Huet confirming OpenAI won't release a separate GPT-5.5-Codex model, as coding capabilities are unified.
A guide on prompting GPT-5.5, including tips for multi-step tasks, migration advice, and starting fresh with new prompts.
Release notes for llm 0.31, a command-line tool for accessing large language models, featuring GPT-5.5 support and new options.
Analysis of why AI and automation are unpopular with the general public despite rising usage numbers.
DeepSeek releases V4 Pro and Flash AI models, offering frontier-level performance at significantly lower costs.
A tool to convert milliseconds to seconds and minutes, created by Simon Willison for LLM report durations.
Simon Willison's newsletter summary featuring tech posts on DeepSeek V4, LiteParse, and Agentic Engineering patterns.
Honker is a Rust SQLite extension implementing Postgres NOTIFY/LISTEN semantics for queues and streams.
Anthropic's postmortem on Claude Code quality issues reveals three bugs affecting user sessions, including a memory-clearing bug causing forgetfulness.
How a single Go process on a gaming PC powers Bluesky's For You feed for 72,000 users using SQLite and Tailscale.
A developer builds a browser-based version of LiteParse, an open-source PDF text extraction tool, using PDF.js and Tesseract.js.
GPT-5.5 is released via Codex; a new LLM plugin uses the semi-official backdoor API to access it through OpenAI subscriptions.
Release of llm-openai-via-codex 0.1a0, a plugin to access OpenAI models via Codex CLI credentials.
Qwen3.6-27B is a new open-weight model delivering flagship coding performance in a compact 27B dense model, outperforming larger predecessors.
