Developer tool · Free · No sign-up
JSON to GraphQL Schema
Generate GraphQL type definitions directly from JSON objects.
JSON Input
GraphQL Schema
type User {
id: Int
name: String
isActive: Boolean
role: String
profile: Profile
posts: [Posts]
}
type Profile {
avatar: String
bio: String
}
type Posts {
title: String
views: Int
}About this tool
Stop manually writing GraphQL type definitions. This tool parses your JSON payload, automatically infers the correct GraphQL data types (String, Int, Float, Boolean), and recursively builds clean `type` definitions for nested objects and arrays. Perfect for rapidly prototyping modern GraphQL backends from existing REST API responses.
Key features
Recursive Type Generation
Automatically creates separate GraphQL types for deeply nested JSON objects.
Smart Array Handling
Correctly infers array types (e.g., [String]) by inspecting the first element.
Custom Root Naming
Define the root query type name to match your GraphQL server architecture.
How to use it
- 1Paste your JSON object or array of objects into the input area.
- 2Enter a name for your root GraphQL type (e.g., User, Post).
- 3View the generated GraphQL schema on the right.
- 4Click copy to paste the schema directly into your GraphQL server code.
Common use cases
- Generating GraphQL schemas for a new Apollo Server or .NET HotChocolate backend.
- Migrating a REST API payload to a strongly-typed GraphQL endpoint.
- Learning how complex JSON structures map to GraphQL type systems.
Frequently asked questions
What GraphQL dialect does this generate?
It generates standard SDL (Schema Definition Language) syntax compatible with all major GraphQL servers including Apollo, GraphQL.js, and .NET HotChocolate.
How does it handle null values in JSON?
If a JSON value is null, the tool cannot infer its true type, so it defaults to 'String' to prevent schema generation errors.
Is my JSON data sent to a server?
No. All parsing and schema generation happens entirely in your browser using native JavaScript. Your data is completely private.
Private and free. Most of our tools run entirely in your browser, so the data you enter isn't uploaded or stored. There's no sign-up, and there never will be — they're built by the Fusion Trail Solutions team to be genuinely useful.
Need a custom tool or web app?
We design and build production-grade web apps, internal tools and SaaS platforms. Tell us what you need.
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