A LITTLE CLARITY FOR YOUR DATA

JSON Schema validator. By the book.

Check JSON types, required fields, and constraints against your schema. Draft-07 and 2020-12 supported.

Your workspace

JSON

Input

Your JSON goes here

18 lines·376 BUTF-8

Output

JSON

{
  "project": "jsonformatkit",
  "description": "A little clarity for your data",
  "version": "1.0.0",
  "isAwesome": true,
  "tools": [
    "Format & validate",
    "Convert & explore",
    "Share something beautiful"
  ],
  "settings": {
    "indentation": 2,
    "sortKeys": false,
    "privacy": "Your data stays yours"
  },
  "madeWith": "care",
  "nextBigIdea": null
}

Formatted JSON376 B

Ctrl↵

JSON Schema

Draft-07 & 2020-12

Schemas are checked locally. External references aren’t fetched.

Looking good. Your JSON is valid.

Object with 11 keys. All brackets, quotes, and commas are in their happy place.

VALID JSON

All done? Take it with you.

Copy your result or download it in a click.

GO A LITTLE FURTHER

More than a pretty print.

A QUICK FIELD GUIDE

Validate JSON types, properties, and constraints

JSON Schema describes the shape of a JSON document. It can require properties, restrict a value to a type, define allowed values, and apply constraints to objects, arrays, strings, and numbers. jsonformatkit checks your JSON against the schema you provide.

Paste the data into JSON input and the schema into JSON Schema, then select Validate schema. The tool reports the first mismatch with a JSON Pointer path and a suggested next step. It checks the data without coercing types, adding defaults, or removing properties.

Draft-07 and Draft 2020-12 are supported, along with common format checks such as email and date-time. Use a 2020-12 $schema declaration for that draft. Internal references are supported; external schema documents are not fetched. Keep schemas within 64 KB and JSON documents within the 2 MB input limit.

How to use JSON Schema validator

Paste your JSON data into the input editor.
Enter a Draft-07 or 2020-12 schema in the schema editor.
Select Validate schema and correct the value or constraint at the reported path.

Up to 2 MB of JSON and 100 nesting levels. URL imports require public HTTPS sources with CORS enabled.

A small example

INPUT

{"age":"30"}

Schema: {"type":"object","properties":{"age":{"type":"integer"}}}

RESULT

/age: must be integer.
Fix the value to use 30 instead of "30".

Frequently asked questions

Which JSON Schema drafts are supported?

Draft-07 and Draft 2020-12 are supported. Declare https://json-schema.org/draft/2020-12/schema in $schema to select the 2020-12 validator. Schemas without that declaration use the Draft-07 validator.

Does schema validation change my JSON?

No. Validation does not coerce strings into numbers, apply default values, or remove additional properties. It checks your data and reports a mismatch so you can decide what to change.

Can a schema reference another document on the web?

External $ref documents are not fetched. Keep referenced definitions inside the same schema and use internal references, such as #/$defs/address. The schema is compiled and checked locally in your browser.

Built around open standards: JSON (RFC 8259), JSON Schema, and YAML 1.2.