JSON to GraphQL Schema Converter
Infer GraphQL Schema Definition Language (SDL) types from JSON samples. Free online tool, 100% client-side.
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What is JSON to GraphQL Schema Converter?
JSON to GraphQL Schema Converter infers GraphQL Schema Definition Language (SDL) type definitions from JSON samples. Paste a JSON object or array and the tool generates ready-to-use type definitions with nested types, arrays, and scalar mapping (String, Int, Float, Boolean, ID). It is perfect for bootstrapping a GraphQL schema from real API responses.
Key Benefits
- Generate valid GraphQL SDL type definitions instantly
- Automatic scalar inference: String, Int, Float, Boolean, and ID
- Nested object extraction into named types
- Array-of-objects merging for unified element types
- 100% client-side, no data leaves your browser
Common Use Cases
- •Bootstrapping a GraphQL server schema from API samples
- •Documenting REST-to-GraphQL migrations
- •Generating types for mock GraphQL servers
- •Learning GraphQL SDL syntax from real data
- •Rapid prototyping of GraphQL APIs
How to Convert JSON to GraphQL Schema
- Input: Paste your JSON object or array into the input area.
- Configure: Set the root type name and toggle nullable fields or ID scalar usage.
- Convert: The GraphQL schema generates automatically as you type or edit options.
- Export: Copy the SDL to clipboard or download it as a .graphql file.
Key Features
- Infer GraphQL SDL types from JSON samples
- Scalar mapping: String, Int, Float, Boolean, and ID
- Nested object extraction into named types
- Array-of-objects field merging for unified element types
- Configurable root type name, nullable fields, and ID scalar
- Copy or download as a .graphql file
Frequently Asked Questions
What is GraphQL SDL?
SDL (Schema Definition Language) is a human-readable syntax for describing GraphQL schemas using type, input, enum, and interface definitions. This tool generates type definitions you can paste directly into a .graphql file.
How does it map JSON types to GraphQL scalars?
Strings map to String, integers to Int, decimals to Float, and booleans to Boolean. When enabled, fields named "id" map to the ID scalar. Null values default to String since their actual type is unknown.
Can it handle nested objects and arrays?
Yes. Nested objects are extracted into separate named types (for example, an "address" field becomes type Address), and arrays of objects are merged into a single element type by unioning their fields.
Does this tool send my data anywhere?
No. All conversion happens 100% in your browser. No JSON data is ever sent to a server or stored.