JSON Schema Validator
Validate JSON data against a JSON Schema to ensure it conforms to a specific structure, data types, and constraints. This tool helps verify API responses, configuration files, and data formats match expected schemas.
When to use this tool
You need to verify JSON payloads match an API contract.
You are testing a schema before rolling it into production.
Examples
Validate an API response shape
Input
Data: { "id": 42, "email": "dev@example.com" }
Schema: requires id:number and email:stringOutput
Valid: data matches the schema
Schema validation checks structure and types, not only JSON syntax.
Developer use cases
Validate incoming webhook payloads against a known schema.
Confirm a config file still conforms after edits.
Common mistakes to avoid
Using a schema draft version incompatible with your validator.
Forgetting to mark required fields in the schema.
Format and behavior notes
Supports standard JSON Schema keywords like type, required, and properties.
Validation checks structure and types, not just syntax.
Related Tools
Frequently Asked Questions
How do I validate JSON against a schema?
Paste your JSON data in one field and your JSON Schema in another. The tool will validate the JSON and show any errors or validation results.
What is JSON Schema?
JSON Schema is a vocabulary that allows you to annotate and validate JSON documents, defining the structure and constraints of JSON data.
What validation errors are shown?
The tool shows detailed validation errors including which properties failed validation, expected vs actual types, and constraint violations.