JSON Schema Validator
Validate JSON documents against JSON Schema with precise path-based error reporting
Paste the JSON instance you want to validate.
Paste a JSON Schema document. Object and boolean schemas are supported.
Validate Schema-Driven Payloads
JSON Schema validation checks whether a payload matches a contract. That makes it useful for API inputs, generated mocks, config validation, and data interchange where shape matters more than optimism.
How It Works
- Paste a JSON document into the left field.
- Paste a JSON Schema into the right field.
- Run validation and inspect the exact instance path that failed.
Common Uses
- Validate API request and response payloads
- Check generated fixtures against a contract
- Verify config shapes before deployment
- Debug schema changes without shipping the schema to a server
Frequently Asked Questions
What does the JSON Schema validator check?
It validates a JSON document against a JSON Schema and reports whether the instance matches the expected structure, required fields, and value constraints.
Can it validate both the schema and the JSON input?
Yes. The tool parses both inputs first, so you get clear errors for malformed JSON in either the instance or the schema before schema validation runs.
Does it support object, array, and boolean schemas?
Yes. The validator accepts standard JSON Schema objects and boolean schemas, which are valid in modern JSON Schema drafts.
What kind of errors does it show?
It shows Ajv validation errors with the instance path and a human-readable message, so you can see exactly which field failed and why.
Is my schema or JSON sent to a server?
No. Validation happens entirely in your browser. The schema and the data stay local, which is the correct amount of paranoia for sensitive API contracts.