simonw/browser-compat-db

# simonw/browser-compat-db Source: [https://simonwillison.net/2026/Jun/24/browser-compat-db/](https://simonwillison.net/2026/Jun/24/browser-compat-db/) **[simonw/browser\-compat\-db](https://github.com/simonw/browser-compat-db)**\. Inspired by Mozilla's[new MDN MCP service](https://developer.mozilla.org/en-US/blog/introducing-mdn-mcp-server/)\-[source code here](https://github.com/mdn/mcp)\- I decided to try converting their comprehensive[mdn/browser\-compat\-data](https://github.com/mdn/browser-compat-data)repository full of browser compatibility data into a SQLite database\. This new GitHub repo includes a Claude Code for web \(Opus 4\.8\)[generated script](https://github.com/simonw/browser-compat-db/blob/main/build_db.py)for doing that using[sqlite\-utils](https://github.com/simonw/sqlite-utils)\. I wanted the resulting ~66MB SQLite database to be available via the GitHub CDN with open CORS headers\. GitHub releases don't have those, but any file stored in a regular GitHub repository does \- so I had Codex Desktop \(GPT\-5\.5\) build[a GitHub Actions workflow](https://github.com/simonw/browser-compat-db/blob/main/.github/workflows/build-db.yml)that builds the database and then force\-pushes it to a`db`"orphan" branch\. You can download the resulting database[from here](https://github.com/simonw/browser-compat-db/blob/db/browser-compat.db), and since it's hosted with open CORS headers you can also[explore it with Datasette Lite](https://lite.datasette.io/?url=https://github.com/simonw/browser-compat-db/blob/db/browser-compat.db#/browser-compat/releases_tree)\.