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JSON to GraphQL Schema Generator

Generate GraphQL schema definitions from JSON data. Automatically infers types, detects IDs, dates, and nested objects. Optionally generates Query and Mutation types.

About JSON to GraphQL Schema

  • Infers GraphQL scalar types (String, Int, Float, Boolean, ID) from JSON values automatically.
  • Detects UUIDs and ID-like fields → ID, dates → DateTime /Date custom scalars.
  • Nested objects become separate GraphQL types. Arrays of objects are merged for complete field coverage.
  • Optionally generates Query type (get by ID, list all) and Mutation type (create, update, delete) with input types.
  • Download the schema as a .graphql file ready for your server.
  • Everything runs in your browser — no data is sent over the network.

Frequently Asked Questions

How do I generate a GraphQL schema from JSON data?
Paste your JSON data into DevBolt's converter and it automatically infers GraphQL type definitions from the structure. Object keys become fields, nested objects become separate GraphQL types, and arrays infer element types. The tool generates complete SDL output including type definitions, Query type with get-by-ID and list operations, and optional Mutation type with create/update/delete operations. Custom scalars like DateTime and Date are detected from ISO string patterns. All generation runs in your browser.
What GraphQL types are inferred from JSON values?
String values become String, integers become Int, floating-point numbers become Float, booleans become Boolean, and fields named id or containing UUID patterns become ID. ISO date strings become DateTime or Date custom scalars. Nested objects become separate named GraphQL types. Arrays of primitives become lists like [String]. Arrays of objects are merged to capture all possible fields. Null values make the field nullable by omitting the ! non-null modifier.
How does the converter handle nested objects and arrays?
Nested objects are extracted into separate named GraphQL types based on the parent field name. For example, a user field containing an address object generates both a User type and an Address type with the user field typed as Address. Arrays of objects merge all array elements to build a complete field set, handling cases where different objects have different keys. Deeply nested structures produce a type hierarchy that mirrors the JSON structure faithfully.

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