Schema Validator
FreeValidate JSON data against a JSON Schema definition
Supports: type, required, properties, items, enum, minimum/maximum, minLength/maxLength, minItems/maxItems, pattern, additionalProperties.
About Schema Validator
Knowing your JSON is syntactically valid is only half the battle; the harder question is whether it has the right fields, types, and shape your system actually expects. The Schema Validator from ToolHub by Codaiman checks a JSON document against a JSON Schema definition so you can enforce structure, not just syntax.
Provide your data and a schema, and the tool reports which constraints pass and which fail, pointing to the specific fields that are missing, mistyped, or out of range. It is ideal for confirming a config matches its contract, testing payloads against a defined schema, or catching breaking changes before they ship. Everything runs in the browser with no signup and returns results instantly, keeping both your data and schema private on your own machine, free to use whenever you need it.
Common uses
- Validating a config file against its published JSON Schema before deployment
- Checking that an API payload matches the contract a schema defines during integration
- Catching missing required fields or wrong types in generated JSON
- Confirming a refactor did not break the expected shape of stored data
- Testing example documents while authoring or revising a JSON Schema
How to use
- 1
Configure options
Set your preferences using the options panel below.
- 2
Click Generate
Click the process button to generate your result instantly.
- 3
Copy or download
Copy the result to clipboard or download it directly to your device.
Why ToolHub?
- Instant error detection
- Detailed error messages
- Standards compliant
FAQ
How is this different from the JSON Validator?
The JSON Validator checks syntax only. This tool checks data against a JSON Schema, verifying required fields, types, and constraints.
Which JSON Schema drafts are supported?
It supports widely used JSON Schema drafts for common keywords such as type, required, properties, and enum.
Does it tell me which field failed?
Yes. Validation errors point to the specific path or field that violates a constraint so you can fix it directly.
Are my data and schema uploaded?
No. Validation runs in your browser, so both the document and the schema remain private.
Can I use Schema Validator on mobile?
Yes — ToolHub is fully responsive and works on iPhone, Android, tablets and all modern browsers. No app install needed.