Skip to content
The WHATWG HTML5 spec as machine-readable JSON
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.


This repository contains Python code that generates machine-readable JSON from the WHATWG HTML Living Standard and Accessible Rich Internet Applications (WAI-ARIA)

This is a work-in-progress and incomplete without a stable format. Contributions are very welcome. Regardless, even in this undeveloped state, this project is still a good basis for many real-world applications.

See also: HTML5 Relax NG schema

Type make to download and parse the spec.

Scope & Mission Statement

Much of HTML5 depends on context and subtle semantics. Checking this may either be extremely computationally expensive, or express the intention of the author in a way that not even a human reader can validate for certain. Additionally, it is challenging to represent complex rules in a language-agnostic way.

This machine-readable specification will, therefore, always be incomplete. Sometimes the best we can practically do is provide human-readable hints in descriptions. Therefore, this machine-readable specification aims to assist a human author and catch obvious errors - but not replace the human author entirely.

Projects using html5spec.json

Please open an issue or pull request to add a project to this list.

You can’t perform that action at this time.