GraphQL Schema to JSON Generator
Instantly convert GraphQL SDL types, enums, and schemas into realistic mock JSON payloads and test fixtures directly in your browser.
At a glance
GraphQL Schema to JSON Generator is a free, client-side tool that converts GraphQL Schema Definition Language (SDL) types into realistic mock JSON data. It parses object types, scalars, enums, and nested relations with circular depth protection. Zero server uploads — all mock synthesis runs locally in your browser.
100% Client-Side In-Browser Mock Data Generator
GraphQL SDL schemas, types, and mock payloads are synthesized completely within your browser sandbox. Zero data leaves your device.
How GraphQL Schema Mock Synthesis Works
Synthesizing mock data directly from GraphQL Schema Definition Language (SDL) types accelerates frontend prototyping, automated testing, and offline API development. Our zero-dependency parser reads your GraphQL type system, extracts object trees and enums, and synthesizes structured JSON fixtures.
AST Schema Parsing
Parses object types, interfaces, inputs, and enums while cleanly discarding comments, docstrings, and field arguments. Core scalars (String, Int, Float, Boolean, ID) map directly to native JSON types.
Cycle & Depth Protection
GraphQL schemas frequently feature recursive relations (e.g. User { friends: [User] }). Configurable recursion depth prevents infinite loops and guarantees graceful payload termination.
Contextual Mocking
Field names containing semantic cues like email, url, avatar, or createdAt automatically generate realistic domain mock data rather than generic placeholder strings.
Why Use This GraphQL Schema to JSON Generator?
How to Use GraphQL Schema to JSON Generator
Paste GraphQL SDL or Upload Schema
Enter your GraphQL schema definitions into the left editor, upload a .graphql file, or load one of our built-in domain presets (Social User Profile, E-Commerce Storefront, Blogging Platform).
Select Target Type & Configure Options
Choose which GraphQL type to generate mock data for from the Target Type dropdown, and customize list array length, max recursion depth, and contextual mocking.
Copy or Download Mock JSON
Review the synthesized mock JSON fixture in the live output panel, copy to clipboard with one click, or download as a .json file.
Social User GraphQL Schema to Mock JSON
Parses User and Profile types alongside Role enum, synthesizing a structured and realistic JSON mock fixture.
enum Role { ADMIN MEMBER }
type Profile {
bio: String
experienceYears: Int
}
type User {
id: ID!
name: String!
email: String!
role: Role!
profile: Profile
}
{
"id": "usr_1001",
"name": "Sample Name",
"email": "user@example.com",
"role": "ADMIN",
"profile": {
"bio": "Detailed mock description for bio",
"experienceYears": 28
}
}
Technical Specifications & Engine Details
| Specification | Details |
|---|---|
| Supported Formats | TEXT/PLAIN, APPLICATION/GRAPHQL, .GRAPHQL, .GQL, .TXT → APPLICATION/JSON, TEXT/PLAIN, .JSON |
| 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
Are my GraphQL schemas sent to an external server?
How does the mock generator handle recursive or circular type references?
Can I choose which GraphQL type to mock?
Does it support GraphQL enums and list modifiers?
Methodology
This tool runs entirely in your browser. The example above shows a representative input and the result it produces.
Last updated .