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JSON Schema Validator

Use this JSON schema validator to validate JSON against a schema online and run JSON schema validation for API contracts, request bodies, response payloads, config files, and sample data with instant field-level errors.

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10 lines • 246 chars

Paste the schema that defines your JSON contract, required fields, allowed values, and API validation rules.

Quick examples

5 lines • 66 chars

Paste the request body, response body, or config JSON you want to validate against the schema.

Quick examples

Usage notes

  • Use this when you need to validate JSON against a schema, not just check whether the JSON parses.
  • If the schema or payload came from logs, docs, or chat, clear syntax problems in /developer-tools/json-validator before schema validation.
  • Open either editor in fullscreen mode when you need to inspect long API payloads or large schemas.
  • Set additionalProperties to false when you want schemas to reject unexpected fields.
  • Schema validation is ideal for API payloads, config files, webhook samples, and contract checks before deployment.

Related pages

JSON ValidatorJSON FormatterGuide: Validate JSON Against a SchemaCompare: JSON Validator vs Schema ValidatorAll Developer Tools

How to Use This Tool

  1. 1Paste or edit a JSON Schema in the first text area.
  2. 2Paste the JSON data you want to test in the second text area.
  3. 3Click Validate JSON Schema to compare the data with the rules in the schema.
  4. 4Review the result and fix any required fields, types, or validation mismatches.

Frequently Asked Questions

How do I validate JSON schema online?
Paste the JSON Schema into the schema editor, paste your JSON data into the data editor, and click Validate JSON Schema. The tool checks required fields, data types, enums, and other schema rules entirely in your browser.
How is JSON schema validation different from JSON validation?
JSON validation checks syntax only. JSON schema validation checks whether valid JSON also follows structural rules such as required fields, data types, enums, and minimum values.
Can I use this as a schema JSON validator for API payloads?
Yes. Paste the schema that defines the payload contract and the request or response body you want to test. Validation happens entirely in your browser.
Does this support required fields and value constraints?
Yes. JSON Schema rules like required, minimum, maximum, enum, pattern, and additionalProperties are supported through Ajv.
Is my schema or data uploaded anywhere?
No. Schema compilation and validation run locally in your browser.