Simon Willison

Mercator ↔ Equal Earth

Simon Willison created an animated transition tool that morphs a map from the Mercator projection to the Equal Earth projection using D3. The project was inspired by the recent UN vote on the Equal Earth map projection and was built with GPT‑6 Astra (medium) in ChatGPT Work. It showcases how modern AI and web technologies can visualize complex geospatial transformations.

Simon Willison
Sep 29

GPT 6.1 Sol: Near-Astra intelligence for a fifth of the price

Simon Willison comments on GPT 6.1‑Sol, describing it as "Near‑Astra intelligence for a fifth of the price." He notes that the model’s pelican illustrations are similar to those of the GPT‑6 family and provides links to the live‑blog of the keynote and to the pelican images. The post is tagged with AI, OpenAI, generative‑AI, LLMs, and playful references to pelican‑riding‑a‑bicycle.

Simon Willison
Oct 22

DE STAAT - FREEDOM (Official Music Video)

The article announces the release of the official music video for "DE STAAT - FREEDOM" by Dutch alternative rock band De Staat. It notes that at 00:44 in the video, visual effects are credited to Matties Grooten of Fake it or Leave it. The post also mentions the video’s presence on Hacker News and tags it with music, AI, generative‑AI, and pelican‑riding‑a‑bicycle.

Simon Willison
Sep 5

Introducing GPT-6 Astra for developers

Simon Willison introduces GPT‑6 Astra, a new model that offers improved attention to detail, better prompt comprehension, and the ability to generate more sophisticated outputs. The model excels at creating 3D renderings, producing detailed scenes such as gardens, shipyards, animals, cityscapes, and even Dyson spheres. Willison highlights its whimsical creativity, noting examples like a pelican wearing a red neckerchief riding a bicycle.

Simon Willison
Oct 20

Battle Drones - a vibe coded RTS with audio-based multiplayer

Battle Drones is a browser‑based, Command & Conquer‑style real‑time strategy game that evolved through 12 major iterations, adding 3D models, varied terrain, random map generation, and both local and online multiplayer via audio synchronization. The game features nine buildings, seven ground vehicles, six aerial vehicles, and three infantry units, with fog of war, area‑effect weapons, and multiple play modes such as skirmish and last‑stand. The project showcases how AI‑assisted coding (primarily Claude) can accelerate game development and introduce innovative multiplayer mechanics using sound.

Simon Willison
Oct 28

The October inflection point for vibe game development

Simon Willison discusses a new inflection point in October 2026 for creating video games using AI, noting that Claude Opus 5.5 now reliably produces compelling 3D models, music, and especially game design. He reports having successfully "vibe coded" four enjoyable games without inspecting the code, and highlights that the real challenge is now generating novel, delightful concepts that AI alone could not conceive. The author compares Opus 5.5’s fun factor to GPT‑6 Astra, which he finds lacking in that regard.

Simon Willison
Sep 4

The Pelican comparison grid for Astra is pretty interesting

Simon Willison tested GPT‑6 Astra by generating SVG pelicans riding bicycles at various reasoning levels and compared the results to GPT‑5.6 Sol, Terra, and Luna. The Astra pelicans consistently outperformed the other models, especially at low and xhigh reasoning levels, and even the Astra max version produced high‑quality images. Astra also used fewer tokens and was roughly twice as expensive as Sol, yet its low‑level output was cheaper and superior to any Sol model.

Simon Willison
Sep 26

Kākāpō Party

Simon Willison presented a closing keynote at the WeAreDevelopers World Congress North America, where he showcased a pixel‑art animation of kakapo parrots celebrating a record‑breaking breeding season in 2026. He used Claude Opus 5.5 to generate the animation from Google‑searched kakapo photos, then employed Claude Code with Playwright to record a 15‑second video of the animated HTML5 canvas, which he embedded in his Keynote slide.

Simon Willison
Sep 7

llm 0.35

The article announces the release of llm version 0.35, which introduces a new OpenAI model named gpt-6-astra for GPT-6 Astra. It highlights the addition of this model to the llm library and tags the release with openai, llm, and gpt-6-astra.

Simon Willison
Sep 7

Video compressor

Simon Willison created a video compressor tool that uses the WebAssembly build of FFMPEG to optimize a demo video of his Equal Earth animation recorded on his phone. He employed Claude Fable 5.1 in Claude Code for web to generate the tool, enabling him to publish the optimized video on his blog. The project showcases how modern web technologies can streamline video processing workflows.

Simon Willison
Sep 2

llm-gemini 0.34

The release of llm-gemini 0.34 introduces the new Gemini 3.8‑Flash model, available in low, medium, and high thinking levels, and fixes an issue where async responses failed to record the resolved model version. The update also notes that Google has released Gemini 3.8‑Flash (and a restricted 3.8 Flash Cyber version) today, with example outputs (pelicans) demonstrating the model’s performance across the different thinking levels. The author highlights Gemini Flash’s speed, low cost, and competence in generating HTML, JavaScript, and Markdown‑SVG content, citing a 13‑second, 1.8‑cent example of an HTML output.

Simon Willison
Aug 16

Markdown SVG upgrades

I started building my markdown-svg-renderer tool in May , but I've since added enough features to it that it's worth talking about here again. It's evolved into my ideal tool for sharing Markdown transcripts that include SVG documents.