ITT
json
schema
validation
developer
json-schema
Updated 2026-02-14

JSON Schema Validator

Validate JSON against JSON Schema (Draft 7, 2019-09) with detailed error reporting.

Tool Area

Instant client-side processing

Schema Validator

Draft 7 & 2019-09 compatible

JSON Schema

JSON Instance

## Validate Your JSON Data Structure JSON Schema is the standard for defining the structure of JSON data. It allows you to enforce rules like "this field must be a number" or "email is required". The **JSON Schema Validator** checks your data against these rules instantly. ### Why Use JSON Schema? 1. **API Contracts**: Ensure your frontend sends data that your backend expects. 2. **Configuration**: Validate complex config files (like VS Code settings) before using them. 3. **Data Quality**: Catch bad data (negative prices, missing IDs) before it enters your database. ### Features - **AJV Engine**: We use the fastest and most standard-compliant validator available. - **Detailed Error Reporting**: We don't just say "Invalid". We tell you: `data.users[0].age should be number`. - **Draft Support**: Supports Draft 7 and Draft 2019-09 standards. - **Real-Time**: Validation runs as you type, giving immediate feedback. ### Privacy First Validation happens 100% in your browser. Neither your Schema nor your Data is ever sent to a server.

Common Questions

QWhat is AJV?

AJV (Another JSON Validator) is the industry-standard node.js/browser library for JSON Schema. It is known for its speed and compliance.

QCan I use custom formats?

Yes. We support standard formats like 'date-time', 'email', 'ipv4', and 'uri'.

QDoes it support $ref?

Currently, we support internal references (definitions within the same schema). External URL references are disabled for security and CORS reasons.

QIs it compatible with OpenAPI / Swagger?

Mostly. OpenAPI schemas are a subset of JSON Schema. Most Swagger definitions will validate correctly here.