JSON Schema Validator

A JSON Schema Validator is a tool that checks whether a JSON document follows a predefined JSON Schema—a formal specification that defines the structure, data types, required fields, and constraints of JSON data.

What does a JSON Schema Validator do?

It validates JSON against rules such as:

• ✅ Required & optional properties
• 🔢 Data types (string, number, boolean, array, object)
• 📏 Value constraints (minLength, maximum, pattern)
• 🔁 Nested object & array validation
• 🚫 Disallowing extra properties
• 🔗 Schema reuse with $ref

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Try out using Best json schema validator

Example

JSON Schema

{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"name": { "type": "string" },
"age": { "type": "integer", "minimum": 18 }
},
"required": ["name", "age"]
}

Valid JSON

json
{
"name": "Pineapple",
"age": 23
}

 Invalid JSON

json
{
"name": "Pineapple",
"age": 15
}

❌ Fails because `age` is less than 18.

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## Why JSON Schema Validation is important

 **API reliability** – ensure requests & responses are correct
 **Security** – prevent malformed or malicious payloads
 **Clear contracts** – frontend & backend agree on data shape
 **Better errors** – precise validation messages

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## Common use cases

* REST & GraphQL API validation
* Form validation
* Configuration file checks
* Database input validation
* CI/CD data checks

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A good **JSON Schema Validator** feature includes:

-  Live validation while typing
-  Clear error messages with line numbers
-  Schema editor + JSON editor side-by-side
-  Support for Draft 7 / 2019-09 / 2020-12
-  Client-side validation for privacy & speed