This is a list of valid HTML boolean and enumerated attributes.
This list is manually compiled from the latest recommendation of the W3C HTML Specification, and the latest recommendation of the WAI-ARIA Specification.
The files are in JSON format for ease of use.
Boolean attributes are attributes that, if the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace.
Enumerated attributes are attributes whose values must be one of a specified list of valid values for that attribute.
Valid values for the type attribute depends on the element that it is defined upon, so a valid value for type on an input element may not be valid on a source element, and vice versa. Additionally, for some elements the values for type are enumerated from locations outside of the HTML Specification (e.g. for source valid MIME Types are to be used), and for this reason, they are not included here.
Feel free to contribute to this repository by adding missing attributes, values, or even suggesting further file formats.