JSON to GraphQL Schema Generator
Instantly transform JSON payloads, API endpoints, and database models into clean, strongly-typed GraphQL SDL schemas with zero server uploads.
At a glance
JSON to GraphQL Schema Generator is a free, client-side tool that converts JSON objects and REST API responses into GraphQL Schema Definition Language (SDL) types. It automatically infers scalar types, unions multi-record arrays, and handles nested entities. Zero server uploads and no installation required — everything executes directly in your browser.
100% Client-Side In-Browser GraphQL Generator
JSON structures, REST API payloads, and database responses are parsed strictly in your local browser sandbox. Zero data transmitted to external servers.
How JSON to GraphQL Schema Inference Works
This developer utility converts arbitrary JSON payloads, REST API responses, and database documents into strongly-typed GraphQL Schema Definition Language (SDL) type blocks. Rather than manually drafting dozens of types, fields, and resolver contracts, our AST inference engine walks your JSON data tree and outputs standards-compliant GraphQL types.
Smart Scalar Mapping
Numbers are automatically classified as Int (32-bit signed integers) or Float (decimals). Identifier keys like id, _id, or userId map directly to the GraphQL ID scalar.
Multi-Record Unioning
When parsing arrays of objects, the generator inspects every record across the collection. Uneven or optional attributes are safely unioned into unified GraphQL type definitions so no field is dropped.
Complete Privacy
All token analysis, schema generation, and code formatting occur 100% within your local browser JavaScript engine. No external network requests are made, keeping proprietary API models completely secure.
Why Use This JSON to GraphQL Schema Generator?
How to Use JSON to GraphQL Schema Generator
Paste JSON or Upload File
Enter your JSON payload into the input editor, upload a .json file, or load one of our domain presets (REST User Profile, E-Commerce Orders, GitHub Repo).
Configure Schema Options
Customize your root type name, toggle ID scalar inference, enable root Query generation, and choose field nullability settings.
Copy SDL or Download
Review the generated GraphQL Schema Definition Language types in the live viewer, copy to your clipboard, or download as a .graphql file.
REST User API Response to GraphQL SDL
Extracts the nested JSON object into distinct Root and Profile GraphQL types with automated ID scalar deduction and array inference.
{
"id": "usr_1024",
"username": "johndoe",
"profile": {
"bio": "Full-stack engineer",
"experienceYears": 5
},
"tags": ["graphql", "typescript"]
}
type Root {
id: ID
username: String
profile: Profile
tags: [String]
}
type Profile {
bio: String
experienceYears: Int
}
Technical Specifications & Engine Details
| Specification | Details |
|---|---|
| Supported Formats | APPLICATION/JSON, TEXT/PLAIN, .JSON, .TXT → TEXT/PLAIN, APPLICATION/GRAPHQL, .GRAPHQL |
| Execution Mode | 100% Client-Side In-Browser (client) |
| Browser Requirements | Requires modern web browser with ECMAScript 6+ and standard DOM Web APIs. |
| Performance Constraints | Runs 100% client-side in browser memory. Performance bounded by local device RAM. |
100% Client-Side Privacy Guarantee
Your files remain strictly on your local device. Zero data is transmitted to external servers.
Frequently Asked Questions
Does this JSON to GraphQL converter send data to an external server?
How are numbers mapped to GraphQL scalar types?
How does the generator handle arrays with uneven or optional fields?
Can I generate a root Query type for Apollo Server or GraphQL Yoga?
Methodology
This tool runs entirely in your browser. The example above shows a representative input and the result it produces.
Last updated .