Next JSON

JSON Schema Generator

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JSON Tools

Nested JSON Parser and Viewer

Decode and view multiple level JSON strings with ease

Convert JSON To Oneline

Convert any JSON string to one line without spaces or indentation

JSON Schema to JSON

Convert a JSON schema to a JSON string

JSON Compare & Diff

Compare two JSON objects and highlight the differences

JSON to TOON Converter

Convert JSON to TOON format for LLM-optimized token efficiency

TOON to JSON Converter

Convert TOON format back to standard JSON

List & Array Tools

Compare Two Lists

Compare two lists to find differences and common items. Also compares text and JSON.

List to Array Converter

Convert input string to an array with different quote styles

How It Works

See how NextJSON can generate a JSON Schema from a JSON object.

Convert JSON to JSON Schema

Generate a JSON Schema from a JSON string, with schema version of <draft 2020-12>

Input
{
  "message": "Welcome to your daily dose of happiness!",
  "mood": "fantastic",
  "dailyAffirmations": [
    "You are capable of amazing things",
    "Today is full of possibilities",
    "Your smile brightens someone's day"
  ]
}
Output
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "message": {
      "type": "string"
    },
    "mood": {
      "type": "string"
    },
    "dailyAffirmations": {
      "type": "array",
      "items": {
        "type": "string"
      }
    }
  },
  "required": [
    "message",
    "mood",
    "dailyAffirmations"
  ]
}
GuideInferring a JSON Schema from Sample JSON: What a Generator Can and Cannot Know

Frequently Asked Questions

What is a JSON Schema?

JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. It describes the structure of your data, including types, required fields, and constraints.

How does the generator infer the schema?

The tool analyzes your JSON structure and infers types from the values—strings, numbers, booleans, arrays, and nested objects. It creates a schema that matches your sample data.

Can I use this schema for validation?

Yes! The generated schema follows JSON Schema draft 2020-12 specification and can be used with validation libraries to ensure incoming data matches the expected structure.

What if my JSON has optional fields?

The generator includes all properties found in your sample. For production use, you may want to edit the schema to mark certain fields as optional by adjusting the required array.

Does this site store my data in the cloud?

No, this site does not store or share your data in the cloud. Your data remains private and is kept locally on your broswer.

This site lacks some useful features that I need. Can you add them?

Yes, we welcome all suggestions! Please feel free to share your feedback using the link at the bottom of the page.