JSON Schema is a declarative language that allows you to annotate and validate JSON documents.

JSON Schema enables the confident and reliable use of the JSON data format.

Benefits #

  • Describes your existing data format(s).
  • Provides clear human- and machine- readable documentation.
  • Validates data which is useful for:
    • Automated testing.
    • Ensuring quality of client submitted data.

Announcements and Feedback Solicitation: Specification Process #

What now? #

Learn, Get help, Shape the Community, Chat, with the JSON Schema team and Community!

Regular Activities #

We hold weekly Office Hours and twice monthly Open Community Working Meetings.

Office Hours are every first Tuesday of the month at 15:00 BST, and by appointment.

Open Community Working Meetings are every Monday at 14:00 PT.

If either of these are cancelled or moved for any reason, we will aim to announce such via the Slack announcement channel and Twitter. See our community calendar (and make sure to check the time zone).

Need more? #

We have our other learning resources, including the Understanding JSON Schema documentation.

About Our Community #

We have an active and growing community. All are welcome to be part of our community, help shape it, or simply observe.

We want to keep our community welcoming and inclusive, so please read our JSON Schema Organizational Code of Conduct. (This is a combination of the Contributor Covenant and IETF BCP 54.)

The JSON Schema team and community are here to help!

At any point, feel free to join our Slack server.

Our Slack server has limited history, so we also use GitHub Discussions.

We monitor the jsonschema tag on StackOverflow.

Project Status #

2022-06-10: A patch release of Draft 2020-12 has been published with no functional changes.

The new IETF document IDs are of the form draft-bhutton-*-01.

2021-02-01: Draft 2020-12 has been published!

The IETF document IDs are of the form draft-bhutton-*-00.

We are using dates for meta-schemas, which are what implementations should use to determine behavior, so we will usually refer to 2020-12 (without the word β€œdraft”) on this web site.

See the Specification page for details about naming and numbering.

Quickstart #

The JSON document being validated or described we call the instance, and the document containing the description is called the schema.

The most basic schema is a blank JSON object, which constrains nothing, allows anything, and describes nothing:


You can apply constraints on an instance by adding validation keywords to the schema. For example, the β€œtype” keyword can be used to restrict an instance to an object, array, string, number, boolean, or null:

{ "type": "string" }

JSON Schema is hypermedia ready, and ideal for annotating your existing JSON-based HTTP API. JSON Schema documents are identified by URIs, which can be used in HTTP Link headers, and inside JSON Schema documents to allow recursive definitions.

JSON Hyper-Schema #

JSON Hyper-Schema is on hiatus / not currently maintained as of 2021.

This allows the team to focus the little time they do donate on JSON Schema core and validation.

We may revisit JSON Hyper-Schema at a later date.

Interested? Check out:

We encourage updating to the latest specification where possible, which is 2020-12.

Questions? Feeling helpful? Get involved on: