Legend

Symbol	Meaning
🟢	Fully implemented
🟡	Partially implemented
🔴	Not implemented
🚫	Not defined in Schema Version.

Compatibility with JSON Schema versions

Validation Keyword/Schema	Draft 4	Draft 6	Draft 7	Draft 2019-09
$ref	🟢	🟢	🟢	🟢
additionalProperties	🟢	🟢	🟢	🟢
additionalItems	🟢	🟢	🟢	🟢
allOf	🟢	🟢	🟢	🟢
anyOf	🟢	🟢	🟢	🟢
const	🚫	🟢	🟢	🟢
contains	🚫	🟢	🟢	🟢
contentEncoding	🚫	🚫	🔴	🔴
contentMediaType	🚫	🚫	🔴	🔴
dependencies	🟢	🟢	🟢	🟢
enum	🟢	🟢	🟢	🟢
exclusiveMaximum (boolean)	🟢	🚫	🚫	🚫
exclusiveMaximum (numeric)	🚫	🟢	🟢	🟢
exclusiveMinimum (boolean)	🟢	🚫	🚫	🚫
exclusiveMinimum (numeric)	🚫	🟢	🟢	🟢
items	🟢	🟢	🟢	🟢
maximum	🟢	🟢	🟢	🟢
maxItems	🟢	🟢	🟢	🟢
maxLength	🟢	🟢	🟢	🟢
maxProperties	🟢	🟢	🟢	🟢
minimum	🟢	🟢	🟢	🟢
minItems	🟢	🟢	🟢	🟢
minLength	🟢	🟢	🟢	🟢
minProperties	🟢	🟢	🟢	🟢
multipleOf	🟢	🟢	🟢	🟢
not	🟢	🟢	🟢	🟢
oneOf	🟢	🟢	🟢	🟢
pattern	🟢	🟢	🟢	🟢
patternProperties	🟢	🟢	🟢	🟢
properties	🟢	🟢	🟢	🟢
propertyNames	🚫	🔴	🔴	🔴
required	🟢	🟢	🟢	🟢
type	🟢	🟢	🟢	🟢
uniqueItems	🟢	🟢	🟢	🟢

Semantic Validation (Format)

Format	Draft 4	Draft 6	Draft 7	Draft 2019-09
date	🚫	🚫	🟢	🟢
date-time	🟢	🟢	🟢	🟢
duration	🚫	🚫	🔴	🔴
email	🟢	🟢	🟢	🟢
hostname	🟢	🟢	🟢	🟢
idn-email	🚫	🚫	🔴	🔴
idn-hostname	🚫	🚫	🔴	🔴
ipv4	🟢	🟢	🟢	🟢
ipv6	🟢	🟢	🟢	🟢
iri	🚫	🚫	🔴	🔴
iri-reference	🚫	🚫	🔴	🔴
json-pointer	🚫	🔴	🔴	🔴
relative-json-pointer	🚫	🔴	🔴	🔴
regex	🚫	🚫	🔴	🔴
time	🚫	🚫	🟢	🟢
uri	🟢	🟢	🟢	🟢
uri-reference	🚫	🔴	🔴	🔴
uri-template	🚫	🔴	🔴	🔴
uuid	🚫	🚫	🟢	🟢

Footnotes

1. Note that the validation are only optional for some of the keywords/formats.
2. Refer to the corresponding JSON schema for more information on whether the keyword/format is optional or not.