SimonWillison.net is the long-running blog of Simon Willison, a software engineer, open-source creator, and co-author of the original Django framework. He writes about Python, Django, Datasette, AI tooling, prompt engineering, search, databases, APIs, data journalism, and practical software architecture. The blog includes detailed notes from experiments, conference talks, and real projects. Readers will find clear explanations of topics such as LLM workflows, SQL patterns, data publishing, scraping, deployment, caching, and modern developer tooling. Simon also publishes frequent micro-posts and TIL entries that document small discoveries and tricks from day-to-day engineering work. The tone is practical and research oriented, making the site a valuable resource for anyone interested in serious engineering and open data.
312 articles from this blog
GitHub Copilot Individual plans are changing with tighter usage limits, paused signups, and new pricing tiers.
Analysis of Anthropic's pricing test moving Claude Code to $100/month plans, causing confusion and backlash.
Testing OpenAI's new ChatGPT Images 2.0 model by generating 'Where's Waldo' style images with a raccoon holding a ham radio.
A critique of AI agents acting too human, lacking stringency and focus, with a call for less human-like behavior.
A blog post about polluting AI training data with pelicans riding bicycles, linked by Simon Willison.
Learn how to fetch data from Datasette into Google Sheets using importdata(), named functions, and Google Apps Script.
Upgraded Claude Token Counter with model comparison, showing token inflation in Opus 4.7 vs 4.6.
Explores the rise of headless services for personal AI agents, with APIs replacing GUIs for better user experience.
Analysis of system prompt changes between Claude Opus 4.6 and 4.7, highlighting new tools, safety updates, and behavioral improvements.
Transforming Anthropic's Claude system prompts into a git timeline for exploring prompt evolution via commit history.
Simon Willison updates his blog-to-newsletter tool to include a new 'beats' content type using a single-shot AI prompt.
Announcing PyCon US 2026 in Long Beach with new AI and security tracks, plus community highlights.
An interactive deconstruction of the 1985 Turbo Pascal 3.02A binary, using AI to decompile and annotate the classic compiler's assembly code.
Kimi.ai congratulates Cursor AI on Composer 2 launch, built on the Kimi-k2.5 model via a commercial partnership.
Analysis of OpenAI's acquisition of Astral, the company behind popular Python tools uv, ruff, and ty, and its implications for the ecosystem.
Explores using Apple's 'LLM in a Flash' research to run a massive 397B parameter AI model locally on a MacBook by streaming weights from SSD.
Report on a prompt injection attack that allowed Snowflake's Cortex AI agent to escape its sandbox and execute malware.
OpenAI introduces GPT-5.4 mini and nano models, detailing their performance, pricing, and a cost example for image description.
A Django core developer warns against over-reliance on LLMs in open-source contributions, emphasizing the need for human understanding.
Mistral AI releases Mistral Small 4, a new 119B parameter open model combining reasoning, multimodal, and coding capabilities.
