
About Simon Willison
Co-creator Django. Creator Datasette and llm CLI. Prolific AI blogger.
Simon Willison is a prominent open-source developer, co-creator of Django, and creator of Datasette and the LLM CLI tool, renowned for his prolific blogging on Python, LLMs, Datasette, and prompt engineering. His work emphasizes practical experimentation with AI tools, data tools, and developer productivity, often blending technical deep dives with personal anecdotes like pelican SVG benchmarks and birdwatching. He critiques AI hype while enthusiastically exploring agentic workflows, pricing models, and open-source integrations.
Biography and Background
Simon Willison is a software engineer based in the San Francisco Bay Area, best known as co-creator of the Django web framework.[1] He created Datasette, a tool for exploring and publishing data, and the LLM CLI, a Python library and command-line tool for interacting with large language models (LLMs).[9][38] Willison maintains an active blog at simonwillison.net, a TIL (Today I Learned) site at til.simonwillison.net, and publishes a weekly newsletter featuring AI experiments, blog posts, and links.[70] He is a frequent conference speaker, including organizing PyCon US 2026 tracks on AI and security.[96]
LLM Experimentation and AI Tools
Willison is a prolific experimenter with LLMs, frequently benchmarking models using whimsical prompts like 'Generate an SVG of a pelican riding a bicycle'.[24][44][62][71][90][197] He tests quantized models, compares pricing (e.g., DeepSeek V4 as cheapest in class[71]), and evaluates local inference on Apple silicon using tools like MLX and Ollama.[47][48][188] Key projects include LLM CLI enhancements for shebangs[9] and reasoning models,[38] plus vibe-coded UIs like LiteParse for PDF extraction.[78] He explores agentic engineering, blurring 'vibe coding' with structured agents,[22] and critiques AI reply bots on Bluesky.[25][105]
Pelican Benchmark Controversy: Willison's SVG pelican tests[72] highlight model creativity but face implicit challenges: do they measure meaningful capabilities or just prompt engineering quirks? Critics might argue they prioritize fun over rigor.[91]
Datasette and Data Tools
Datasette remains a core project, with recent TILs on Google Sheets integration via importdata() and custom functions.[101] Willison pushes code updates frequently[127][128][156] and stars related repos like sqlglot and syntaqlite.[143][169] He envisions RSS-based search engines reviving Feedster concepts.[32]
Developer Productivity and AI Coding
Willison champions AI agents for tedious tasks like refactors[190] and TDD-driven features when codebases provide style precedents.[185] He discusses Claude Code pricing shifts,[81][93] Anthropic system prompt diffs,[98], and Zig's AI contribution ban rationale—prioritizing contributor growth over code quality.[33][34] GitHub activity shows stars in AI orchestration (Flyte[124]), workflows (Prefect[132]), and uv migration tools.[117][163]
AI in Open Source Challenge: Zig's ban[33] aligns with Willison's respect for maintainer time,[29] but he notes it sidesteps LLM code quality debates—countered by evidence of AI finding real vulnerabilities.[196]
AI Industry Analysis
Willison dissects pricing (GitHub Copilot pauses[81], Claude token hikes[100]), deals (xAI/Anthropic Colossus[16]), and announcements (OpenAI-Microsoft revenue share[51]). He highlights Gen Z's heavy AI use despite negative feelings,[58][75] critiques 'zombie internet' bots,[10] and notes AGI glimpses in emergent behaviors.[62]
Personal Interests and Life
Beyond tech, Willison tap dances in community college recitals,[12] birdwatches (white-crowned sparrows[30], iNaturalist integration[27]), visits factories (Heath Ceramics[1]), and enjoys shows like Widow's Bay[7] and Crazy Ex-Girlfriend.[14] He praises San Jose's immigrant food scene countering 'ghost town' narratives.[186][187]
Structured Claims and Challenges
From analyzed content, Willison claims like 'AI agents excel at replicating familiar code patterns'[185] face counters: agents struggle with novel tasks without precedents (medium strength). His ChatGPT voice wishes[183] are challenged as casual vs. formal proposals (moderate).[counter-claims]
LLM Benchmarking and Prompt Engineering
Obsessive testing of LLMs via SVG animal prompts (pelicans on bikes, opossums on e-scooters) to compare models, quantization, and creativity.
AI Tool Development (LLM CLI, Datasette)
Developer Productivity with AI Agents
AI Pricing and Industry News
Critiques of AI Hype and Social Impacts
Open Source and GitHub Ecosystem
Every entry that fed the multi-agent compile above. Inline citation markers in the wiki text (like [1], [2]) are not yet individually linked to specific sources — this is the full set of sources the compile considered.
- At a guess, about a 50th of a hamburgerbluesky_post · 2026-06-14
- Let's take a very pessimistic estimate - assume Fable is 2x the energy/water usage of Opus (so 10 ra...bluesky_post · 2026-06-14
- Depending on which almond growing water usage estimate you believe that's between 1/14th and 1/5th o...bluesky_post · 2026-06-14
- It's now possible to compile Python extensions (C, C++, Rust etc) to WebAssembly and distribute them...bluesky_post · 2026-06-14
- I got fed up of waiting for OpenAI to bring their much improved gpt-realtime-2 voice conversation mo...bluesky_post · 2026-06-13
- Wow that's a fine pelicanbluesky_post · 2026-06-12
- Yes that should work pretty well, maybe I should give that thing more of a trybluesky_post · 2026-06-12
- It was in "auto" modebluesky_post · 2026-06-12
- After two days with Claude Fable 5 the best way I can describe it is "relentlessly proactive" - here...bluesky_post · 2026-06-12
- This right here is a pretty elegant solution to the problem of wanting to capture measurements from ...bluesky_post · 2026-06-12
- New Datasette release: 1.0a33, which finally brings documents the ?_extra= JSON API mechanism and br...bluesky_post · 2026-06-11
- Since the JSON extras API is a little hard to explain without an example I also had Fable 5 and GPT-...bluesky_post · 2026-06-11
- They released Fable 5 and Mythos 5 - and described Mythos as "Fable 5’s capabilities without the saf...bluesky_post · 2026-06-10
- I've stayed clear of those because I'm worried about how many tokens they would burn, plus I still r...bluesky_post · 2026-06-10
- I can't talk for other professions, but it further changes what being a professional software engine...bluesky_post · 2026-06-10
- Almost alwaysbluesky_post · 2026-06-10
- Wrote up my initial impressions of Claude Fable 5 - it has a big model smell: slow, expensive and ca...bluesky_post · 2026-06-10
- Here are Fable's pelicans for the different thinking effort levels, plus how much each one cost to g...bluesky_post · 2026-06-10
- A TIL on using agentsview.io to calculate token spending with Claude Fable 5 despite that model not ...bluesky_post · 2026-06-09
- I tried to visit that one during PyCon US in Pittsburgh last year but it turns out you have to book ...bluesky_post · 2026-06-09
- I've been running Claude Code on the default "high" level, haven't tried the others yetbluesky_post · 2026-06-09
- It doesn't handle any Python package that can't be inlined into a single pure Python string For num...bluesky_post · 2026-06-09
- I may have finally found the Python-in-a-sandbox solution I've been looking for... here's my latest ...bluesky_post · 2026-06-06
- You can try it out like this: uvx micropython-wasm -c 'print("Hello world")'bluesky_post · 2026-06-06
- Today on TikTok: Chinese truck selling thirst traps www.tiktok.com/@chenglongtr...bluesky_post · 2026-06-04
- Today on TikTok: Chinese truck selling thirst traps www.tiktok.com/@chenglongtr...bluesky_post · 2026-06-04
- My guess is that it's per billable vendorbluesky_post · 2026-06-04
- Presumably each of Anthropic and OpenAI and Cursor have enterprise plans where you can set per-user ...bluesky_post · 2026-06-04
- Uber reportedly now caps coding agents at $1,500/month per employee per tool - seems sensible to me,...bluesky_post · 2026-06-03
- My problem is more that it FAKES intent - if I'm going to be convinced of something I want it to com...bluesky_post · 2026-06-02
- I mean yeah, tokenmaxxing leaderboards were an absurdly stupid trend and deserve to go extinct alrea...bluesky_post · 2026-06-02
- Right now if you want a big PR hit being a company that says "we're pulling back on our AI spend" is...bluesky_post · 2026-06-02
- In PR terms, do you think the Uber COO messed up when he let slip that Uber were reconsidering the R...bluesky_post · 2026-06-02
- Tone didn't really feel confrontational to me, the thing I care about is that people are arguing in ...bluesky_post · 2026-06-02
- Flask was Armin! I'm partially responsible for Djangobluesky_post · 2026-06-02
- Thanks, just fixed itbluesky_post · 2026-06-02
- Depends on the content I'm fine with LLMs writing code documentation - the qualities I care about t...bluesky_post · 2026-06-02
- Have you seen any better expamples of organizations "pulling back" than that (in my opinion quite fl...bluesky_post · 2026-06-02
- Parenting is an interesting one because, on the one hand, billions of people have done it and shared...bluesky_post · 2026-06-01
- Not to mention different cultures have wildly different parenting standards - advice for rising a ch...bluesky_post · 2026-06-01
- I'm talking about AI-generated slop Interestingly it's rare in comments, but increasingly common in...bluesky_post · 2026-06-01
- I'm pretty sure most Hacker News upvotes are based on the title only, without visiting the articlebluesky_post · 2026-06-01
- The best heuristic I have is to check for other posts or article by the same "author" - the slop acc...bluesky_post · 2026-06-01
- Effectively, I am looking for inhuman consistency!bluesky_post · 2026-06-01
- Hacker News has an alarmingly high tolerance for slop content these days It also has social norms a...bluesky_post · 2026-06-01
- I really dobluesky_post · 2026-05-31
- No I think they are proportional - the December date is 31st so effectively the same as January 1st,...bluesky_post · 2026-05-30
- I fed your feedback to Claude Opus 4.8 and it had a bit of a spin-out about it (since I was saying t...bluesky_post · 2026-05-30
- That's a better image so I've dropped that into my blog post to replace the old onebluesky_post · 2026-05-30
- Not if they'd like to avoid the coverage of their S-1 being mainly about how it demonstrates their d...bluesky_post · 2026-05-30
- For context, the question I had asked was "I need the most accurate, most recent and most credible i...bluesky_post · 2026-05-30
- That one was GPT-5.5 Probluesky_post · 2026-05-30
- Hah, here's another one, this time I asked about the Iran war: "I'm cautious about the sources since...bluesky_post · 2026-05-30
- I don't know enough about financial engineering to comment, I believe it could be revenue-for-the-qu...bluesky_post · 2026-05-29
- I take the first result I get, it's very unscientific - I've been planning a version that picks the ...bluesky_post · 2026-05-29
- I probably would - very glad I don't have to make that decision though!bluesky_post · 2026-05-29
- Not yet, I think most companies are still very much figuring out what this stuff is useful for (and ...bluesky_post · 2026-05-29
- Mostly yes - I think complete lies would be securities fraud I'm suspicious that they haven't expl...bluesky_post · 2026-05-29
- I suspect the Uber story was overblown - it's pretty weak when you dig into the sources of the data ...bluesky_post · 2026-05-29
- Already mentioned that in my postbluesky_post · 2026-05-29
- Does that mean you think there was a company that has had faster revenue growth than Anthropic and A...bluesky_post · 2026-05-29
- Supposedly Anthropic are set to have their first profitable quarter. WSJ this time: www.wsj.com/tech...bluesky_post · 2026-05-29
- Anthropic's self-reported run-rate revenue growth is wild - Axios Jim VandeHei said he couldn't find...bluesky_post · 2026-05-29
- Notes on Claude Opus 4.8, which Anthropic call "a modest but tangible improvement" - plus pelicans r...bluesky_post · 2026-05-29
- To clarify, I spend $200/month but it would cost me $2100/month if I wasn't getting the huge subscri...bluesky_post · 2026-05-29
- My atom feed should only include releases and sightings when they have extra commentary attached - w...bluesky_post · 2026-05-28
- If that happens we'll see the evidence pretty soon - my hunch is they'll paybluesky_post · 2026-05-27
- Given the recent burst of activity around enterprise pricing and contracts, I think April 2026 was t...bluesky_post · 2026-05-27
- When I woke up this morning I didn't think I'd be spending a bunch of time today getting familiar wi...bluesky_post · 2026-05-26
- ... plus a bonus section of transcript from the Oxide and Friends 2026 predictions episode in Januar...bluesky_post · 2026-05-26
- weird, it looks like this for mebluesky_post · 2026-05-26
- That's one thing that really impressed me: the explanations of how it worked all looked perfectly cr...bluesky_post · 2026-05-26
- That's the point: you give it something that's happened recently which is outrageous and watch as it...bluesky_post · 2026-05-25
- Fun new feature in Datasette 1.0a30 - a "jump to" menu, also available by the "/" keyboard shortcut,...bluesky_post · 2026-05-25
- Plugins can also affect the empty state of the new menu - the latest datasette-agent adds a form for...bluesky_post · 2026-05-25
- I heard that's one of the best places in the Bay Area to get a proper haggis for Burns Nightbluesky_post · 2026-05-24
- "then explicitly tells the agent not to trust the analysis in the issue" - have you explored having ...bluesky_post · 2026-05-24
- But they were NOT spying through microphones, they got punished by the FTC for saying that they were...bluesky_post · 2026-05-22
- Presumably because your work phone and your home phone had advertising profiles that were connected ...bluesky_post · 2026-05-22
- I like how this McSweeney's headline puts it www.mcsweeneys.net/articles/cal...bluesky_post · 2026-05-22
- @futurism.com important update to your story from September 2024 futurism.com/the-byte/fac... - the ...bluesky_post · 2026-05-22
- Here's the FTC press release: www.ftc.gov/news-events/... "this service did not, in fact, listen in...bluesky_post · 2026-05-22
- cc @404media.co you wrote about this one as well www.404media.co/cmg-cox-medi...bluesky_post · 2026-05-22
- It's self-hostable and collaborative - I think this will get a whole lot more interesting as we wire...bluesky_post · 2026-05-22
- Yes, if they run the open source package themselves - I've tested it against OpenAI and Anthropic an...bluesky_post · 2026-05-22
- I've been experimenting with agents and the Datasette JSON API, which works pretty well - I'm contem...bluesky_post · 2026-05-22
- That's really useful, thanks - I've spent almost no time iterating on the system prompt so farbluesky_post · 2026-05-22
- I released the first alpha of Datasette Agent - a conversational AI assistant for Datasette that can...bluesky_post · 2026-05-21
- Here's more about Datasette Agent on my blog simonwillison.net/2026/May/21/...bluesky_post · 2026-05-21
- I don't have much to say about this year's Google I/O because I prefer to write about products that ...bluesky_post · 2026-05-20
- Sounds like they just haven't quite got it ready for release yet, they said next monthbluesky_post · 2026-05-20
- It's cheaper per-token but more expensive to run the full Artificial Analysis benchmark Here are co...bluesky_post · 2026-05-20
- Top quality commentary on that pelican on Hacker News news.ycombinator.com/item?id=4819...bluesky_post · 2026-05-20
- My notes on Gemini 3.5 Flash - 3x the price of Gemini 3 Flash but Google are planning to use it for ...bluesky_post · 2026-05-19
- I'd need to catch up on a LOT of American reality TV before I could pull that off A Great British B...bluesky_post · 2026-05-19
- (Or Australian Lego Masters)bluesky_post · 2026-05-19
- I often enjoy torturing LLMs with questions like this since the underlying facts are way outside the...bluesky_post · 2026-05-17
- To prepare for my #PyConUS lightning talk this afternoon I decided to track down ALL of the names th...bluesky_post · 2026-05-16
- When I said TikTok was full of lighting talks this one about New Orleans is exactly the kind of thin...bluesky_post · 2026-05-16
- I was on a factory tour of Heath Ceramics in Marin, CA the other day and I asked the tour guide if I...bluesky_post · 2026-05-13