JSON Schema Validator (Draft-07)

Validate JSON data against JSON Schema Draft-07 — instant structural validation in your browser

What Is JSON Schema Validation?

JSON Schema validation checks whether a JSON document conforms to a predefined schema that specifies the expected structure, data types, required fields, value constraints, and patterns. JSON Schema Draft-07 is one of the most widely adopted versions, supported by validators in every major programming language. It lets you define rules like required fields, string patterns (regex), numeric ranges, array lengths, enum values, and conditional constraints.

Schema validation is essential for API contract enforcement, form input validation, configuration file verification, and data pipeline quality checks. Instead of writing custom validation code for every data structure, you define a schema once and use it everywhere — in your API gateway, backend services, frontend forms, and CI/CD pipelines. A single schema serves as both documentation and enforcement, catching invalid data before it causes runtime errors or data corruption.

How to Validate JSON Against a Schema

1. Paste your JSON Schema (Draft-07 format) into the schema editor panel
2. Paste the JSON data you want to validate into the data editor panel
3. Click Validate to check the data against the schema
4. Review results: green checkmark for valid data, red markers for each validation error with details
5. Fix reported issues — each error includes the property path, expected type, and actual value

Why Use PinusX for JSON Schema Validation?

PinusX runs the schema validator entirely in your browser with 100% client-side processing. Your schemas and data documents never leave your device. This is especially important when validating API payloads, configuration files, or data exports that contain sensitive business logic, user data, or security credentials. In November 2025, jsonformatter.org leaked over 80,000 user credentials that users had pasted into their server-based tool. PinusX eliminates this vulnerability because the validation engine runs locally in your browser tab using JavaScript — no data is transmitted, no logs are created, no third-party servers are involved.

Frequently Asked Questions

What is JSON Schema Draft-07?

Draft-07 is a specific version of the JSON Schema specification published in 2018. It is the most widely supported draft with mature implementations in JavaScript, Python, Java, Go, and other languages. It includes features like if/then/else conditional validation, readOnly/writeOnly markers, and content encoding declarations.

What schema constraints can I validate?

Draft-07 supports type checking (string, number, boolean, array, object, null), required properties, string patterns (regex), format validators (email, date, URI), numeric ranges (minimum, maximum), string length limits, array length and uniqueness constraints, enum values, allOf/anyOf/oneOf combinators, and conditional if/then/else logic.

Can I validate against other draft versions?

This tool specifically validates against Draft-07, which is the most commonly used version. If your schema uses a different draft (Draft-04, Draft-06, or 2019-09/2020-12), some keywords may behave differently. Check your schema's $schema field to confirm which draft you are targeting.

How do I create a JSON Schema?

Start with a schema object containing $schema, type, and properties. Define each property with its type and constraints. Mark required fields in the required array. You can build schemas incrementally — start with types and required fields, then add patterns, ranges, and conditional logic. Many tools can also generate schemas from sample JSON data.

What happens when validation fails?

The validator reports every error with the JSON path of the failing property, the constraint that was violated, the expected value or type, and the actual value found. Multiple errors are reported simultaneously so you can fix all issues at once rather than iterating one error at a time.

Your data never leaves your browser. 100% client-side processing.