JSON Schema Validator Online
Validate JSON documents against formal schemas using the industry-standard AJV engine. Supports Draft-07, Draft-2019-09, and Draft-2020-12. Runs privately in a background worker thread.
What is JSON Schema?
JSON Schema is a declarative vocabulary that allows you to annotate and validate JSON documents. It provides a formal contract for what properties are expected, their data types, range boundaries, string formats, and relationships inside your structures.
How Schema Validation Works
To validate a JSON target file, you define a schema describing structural rules. The validator evaluates whether the target meets those criteria. When a constraint (such as a missing required field or incorrect value type) is violated, the engine raises structured validation error diagnostics.
This online tool isolates compile and run-time validation on separate Web Worker background threads. This ensures that validation of large schemas never hangs or degrades the responsive rendering of your browser UI.
Draft Versions Supported
- Draft-07: One of the most widely adopted older versions, commonly used in enterprise APIs and OpenAPI v3 specifications.
- Draft-2019-09: Added powerful features like dynamic anchoring,
dependentRequired, and robust keyword subdivisions. - Draft-2020-12: The latest major release featuring fully decoupled schemas and expanded keyword combinations.
Common Validation Errors
Schema rules capture common structural issues:
type: Value type does not match definition (e.g. expected number, received string).required: A required key was missing from the parent object.additionalProperties: Document contains unrecognized keys when forbidden by the schema.pattern: String value failed to match the defined regex pattern constraint.
Frequently Asked Questions
Is my data sent to any servers?
No. JSON Suit processes all files completely locally inside your browser via secure client-side Web Workers. Your documents, schemas, and values never leave your device.
Does it support formats like email, date, and UUID?
Yes, full standard format validation is enabled across all three supported draft versions.
Related JSON Suit Utilities
Learning Resources & Tutorials
Master the intricacies of parsing and schemas for JSON Schema Validator.
Suggested Learning
Intro to JSON Schema Specification
Designing Safe API Payloads using JSON Linter
Debugging JSON syntax issues instantly
Integration Examples
Typical developer setting schema.
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"port": { "type": "integer", "default": 3000 }
}
}Developer Workflow
How JSON Schema Validator fits inside the development and debugging lifecycle.
Ingest XML
Load XML string or document
Convert
Convert to native JSON
Format
Beautify JSON structures
Integrate
Consume JSON in codebases
Active Stage