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.