How to Validate JSON Schema

Validate JSON data against a JSON Schema definition. Check types, required fields, patterns, and constraints. Free online validator with detailed error messages.

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Step-by-Step Guide

1

Enter your JSON Schema

Paste your JSON Schema definition in the schema editor. The tool supports Draft 4, 6, 7, and 2020-12 specifications. Start from a template or write your own schema from scratch.

2

Paste your JSON data

Enter the JSON data you want to validate in the data editor. This is the actual payload — an API response, config file, or user input — that should conform to the schema.

3

Run validation

Click validate to check your data against the schema. The tool checks types, required properties, string patterns, numeric ranges, array constraints, and conditional rules.

4

Fix reported errors

Each validation error shows the exact JSON path, the rule that failed, and what was expected. Fix issues one by one or use the error summary to prioritize the most critical problems.

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Frequently Asked Questions

What is JSON Schema?
JSON Schema is a vocabulary that lets you define the structure, data types, and constraints of JSON data. It is used to validate API payloads, configuration files, and form data — like a contract that your JSON must follow.
Which JSON Schema draft versions are supported?
The tool supports Draft 4, Draft 6, Draft 7, and Draft 2020-12. It auto-detects the version from the $schema keyword, or you can select it manually.
Can I validate nested objects and arrays?
Yes. JSON Schema handles deeply nested structures, array item validation, conditional schemas (if/then/else), and cross-field dependencies. All errors include the full JSON path so you can locate issues in complex data.
Related Reference

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