MDN data
Maintained by the MDN team at Mozilla.
This repository contains general data for Web technologies.
This data is used in MDN documentation, to build information boxes or sidebar navigation. External tools have started to make use of this data as well. For example, the CSSTree CSS parser.
Repository contents
There's a top-level directory for each broad area covered: for example, "api", "css", "svg". Inside each of these directories is one or more JSON files containing the data.
api
Contains data about Web APIs:
- API inheritance (interface inheritance and mixin implementations)
css
Contains data about:
- CSS at-rules
- CSS properties
- CSS selectors
- CSS syntaxes
- CSS types
- CSS units
Read more about CSS data and the format of the files.
l10n
The l10n folder contains localization strings that are used in the various json files throughout this repository.
Problems?
If you find a problem, please file an issue.
Contributing
We're very happy to accept contributions to this data. Please familiarize yourself with the schema for the data you're editing, and send us a pull request. See also the Contributing file for more information.
See also
- https://github.com/mdn/browser-compat-data for compatibility data for Web technologies.

Formed in 2009, the Archive Team (not to be confused with the archive.org Archive-It Team) is a rogue archivist collective dedicated to saving copies of rapidly dying or deleted websites for the sake of history and digital heritage. The group is 100% composed of volunteers and interested parties, and has expanded into a large amount of related projects for saving online and digital history.
