JSON Schema Validator
Validate JSON data against JSON Schema online. Supports Draft 4/6/7/2019-09/2020-12 and displays validation errors with JSON path, message, and expected value.
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How to Use
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- 1
Enter JSON Schema
Type or paste your JSON Schema into the left editor, or choose from the preset examples. Supports Draft 4/6/7/2019-09/2020-12.
- 2
Enter JSON Data
Type or paste the JSON data you want to validate into the right editor. Preset sample data is also available.
- 3
Review Validation Results
Validation runs in real time. If errors are found, they are listed with the JSON path, error message, and expected type or value.
JSON Schema
JSON Data
Validation Result
Enter JSON Schema and JSON data to validate
About JSON Schema Validator
JSON Schema Validator checks JSON payloads against JSON Schema specifications instantly in your browser. Use it to validate OpenAPI request/response bodies, test schema definitions before wiring them into ajv or Zod, or debug why a Stripe webhook payload or AWS EventBridge event fails validation in your CI pipeline. Supports all drafts from Draft 4 through 2020-12 with auto-detection via the $schema property, and surfaces every error with the exact JSON Pointer path so you can fix issues without guessing.
Key Features
- Supports all Draft versions: 4, 6, 7, 2019-09, and 2020-12
- Real-time validation with instant error detection
- Displays JSON path, error message, and expected value for each error
- Separate syntax error detection for both schema and data
- Built-in preset schemas and sample data to get started quickly
Common Use Cases
- Validate OpenAPI request/response body schemas against real API payloads before wiring them into ajv or Zod
- Debug why a Stripe webhook event or AWS SNS notification fails schema validation in your Lambda function
- Test Draft 2020-12 schemas with unevaluatedProperties or $dynamicRef before adopting them in a new microservice
- Validate GitHub Actions workflow config-like JSON structures or Renovate bot configuration against a custom schema
- Run quick schema smoke tests during CI — paste the schema and a sample payload to confirm the contract before merging
Frequently Asked Questions
Which Draft version should I use?
For new projects, Draft 2020-12 or 2019-09 is recommended. ajv (the most popular Node.js validator) supports both with the ajv-formats plugin. OpenAPI 3.1 schemas use a subset of Draft 2020-12. In auto-detect mode, the validator reads the $schema attribute from your schema to determine the version automatically.
Is my input data sent to a server?
No. Validation runs locally using ajv compiled in your browser. You can safely paste production payloads, internal API contracts, or PII-containing test data.
What format are the error JSON paths in?
Error paths are displayed in JSON Pointer format (RFC 6901). For example, "/user/age" refers to the age property of the user object. Errors at the root object are shown as "/". This matches the instancePath format returned by ajv, so you can correlate errors directly with your application validator output.
Can I validate OpenAPI schemas directly?
You can validate the JSON Schema components inside an OpenAPI spec, but full OAS structural validation (paths, operations, $ref resolution) is out of scope here. Use the OpenAPI Validator tool for complete OpenAPI spec validation.