JSON to GraphQL Schema Converter
Convert JSON objects to GraphQL SDL type definitions instantly. Handles nested objects, arrays, non-null fields, and all scalar types.
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What Is a JSON to GraphQL Schema Converter?
GraphQL uses a Schema Definition Language (SDL) to describe the shape of your data. A JSON to GraphQL schema converter reads a JSON object and generates SDL type definitions — including nested types for every nested object, array types with [] notation, and non-null ! markers for non-null fields.
How to Use
- Paste your JSON object into the left textarea.
- Optionally set a custom root type name (default: Root).
- GraphQL SDL types are generated automatically as you type.
- Click Copy to paste the schema into your GraphQL project.
Features
- Maps JSON types to GraphQL scalars: String, Int, Float, Boolean.
- Nested objects generate separate named types automatically.
- Arrays map to GraphQL list types using
[Type]notation. - Non-null fields are marked with
!; null JSON values stay nullable. - Configurable root type name for cleaner schema output.
- Runs entirely in your browser — no data is sent to any server.
FAQ
What GraphQL scalars does this tool use?
JSON strings map to String, integers to Int, floats to Float, and booleans to Boolean. These are all built-in GraphQL scalars that work with any GraphQL server.
How are non-null fields determined?
Fields whose JSON value is not null are marked as non-null with !. Fields with a null value are left nullable. You can adjust this in the generated schema.
Does this generate queries or mutations?
No — this tool generates only type definitions (SDL). You add Query, Mutation, and Subscription types manually to wire them into your schema.