$comment : String



This keyword reserves a location for comments from schema authors to readers or maintainers of the schema.

Value This keyword must be set to a string
Kind Reserved Location
Applies To Any
Dialect 2020-12
Changed In None
Introduced In Draft 7
Vocabulary Core
Specification https://json-schema.org/draft/2020-12/json-schema-core.html#section-8.3
Metaschema https://json-schema.org/draft/2020-12/meta/core
Official Tests None
Default None
Annotation None
Affected By None
Affects None

The $comment keyword is used to provide a way for schema authors to include explanatory or clarifying comments within the schema itself. However, it’s important to note that JSON Schema implementations are required to NOT add meaning to $comment, and not even collect it as an annotation. Additionally, they may even ignore or strip it out entirely. Therefore, $comment is primarily useful for leaving notes to future editors of the schema rather than communicating with users of the schema.

  • Implementations ignore $comment during validation.
  • It will not even be collected as an annotation.
  • It can be placed anywhere within a JSON Schema to provide additional context or explanation.
  • Some tools might even remove this keywords for size optimization. Learn more


Schema with '$comment' keyword Schema
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "$comment": "This property stores the person's full name."
    "age": {
      "type": "integer",
      "$comment": "Age must be a positive integer value."
Valid Comments have no effect on validation Instance
  "name": "John Doe",
  "age": 30
Valid Comments have no effect on validation Instance
  "name": "John Doe",
  "age": -10
  • Although the ‘age’ property in the above instance does not adhere to the described comment, the instance is still considered valid.