Willison Releases SQLite Database for Browser Compatibility Data
- •Simon Willison released the browser-compat-db repository on GitHub on June 24, 2026.
- •The project converts MDN browser compatibility data into a 66MB SQLite database file.
- •The build workflow was generated using Claude Code (Opus 4.8) and GPT-5.5 (Codex Desktop).
On June 24, 2026, Simon Willison released a new GitHub repository called browser-compat-db. The project converts Mozilla’s extensive mdn/browser-compat-data repository, which tracks browser support for web features, into a standalone SQLite database. The transformation script was generated using Claude Code for web (Opus 4.8) and sqlite-utils.
The resulting SQLite database is approximately 66MB in size. To ensure the file is accessible via the GitHub CDN with open CORS headers (a mechanism allowing browsers to request data from different origins), Willison utilized a workflow built by Codex Desktop (GPT-5.5). This GitHub Actions workflow automatically builds the database and pushes it to a dedicated orphan branch, enabling users to download the file or explore it directly through Datasette Lite.