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.
Decode and view multiple level JSON strings with ease
Convert any JSON string to one line without spaces or indentation
Convert a JSON schema to a JSON string
Compare two JSON objects and highlight the differences
Convert JSON to TOON format for LLM-optimized token efficiency
Convert TOON format back to standard JSON
See how NextJSON can generate a JSON Schema from a JSON object.
Generate a JSON Schema from a JSON string, with schema version of <draft 2020-12>
{
"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"
]
}{
"$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"
]
}
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.
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.
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.
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.
No, this site does not store or share your data in the cloud. Your data remains private and is kept locally on your broswer.
Yes, we welcome all suggestions! Please feel free to share your feedback using the link at the bottom of the page.