GraphQL to TypeScript
LiveGenerate TypeScript types and interfaces from GraphQL schema definitions.
Understanding TypeScript
GraphQL schemas and queries define data structures that TypeScript applications need typed access to. Manually writing TypeScript types that match GraphQL schemas is tedious and error-prone — when the schema evolves, types must be updated in sync. Auto-generating TypeScript interfaces from GraphQL schemas, queries, and mutations ensures type safety between the API layer and the frontend application, catching data access errors at compile time rather than runtime.
Convert GraphQL schema definitions (SDL) into TypeScript interfaces and types automatically. Handles object types, input types, enums, unions, interfaces, and nullable fields. Saves hours of manual type writing for GraphQL APIs.
The Devkitr GraphQL to TypeScript Converter generates TypeScript types, interfaces, and enums from GraphQL schemas, queries, and mutations. Paste a GraphQL schema definition or query document to get typed TypeScript definitions that match the GraphQL structure exactly.
In a typical development workflow, GraphQL to TypeScript becomes valuable whenever you need to generate typescript types and interfaces from graphql schema definitions. Whether you are working on a personal side project, maintaining production applications for a company, or collaborating with a distributed team across time zones, having a reliable browser-based conversion tool eliminates the need to install desktop software, write one-off scripts, or send data to third-party services that may log or retain your information. Since GraphQL to TypeScript processes everything locally on your device, your data stays private and your workflow stays uninterrupted — open a browser tab, paste your input, get your result.
Key Features
Schema Type Generation
Converts GraphQL type definitions, input types, enums, and unions into corresponding TypeScript interfaces and union types.
Query Result Types
Generates TypeScript types for specific query results, typing only the fields selected in the query rather than the entire schema type.
Enum Mapping
Converts GraphQL enums to TypeScript enums or string literal union types (type Status = "ACTIVE" | "INACTIVE") based on your preference.
Nullable Field Handling
Maps GraphQL nullability rules — non-null (!) fields become required TypeScript properties, nullable fields become Type | null.
How to Use GraphQL to TypeScript
Paste GraphQL Schema or Query
Enter a GraphQL schema definition (type User { ... }) or a query/mutation document with field selections.
Configure Options
Choose between interface and type alias output, enum style (TypeScript enum vs string union), and nullable handling.
Review Generated Types
Check nested types, enum mappings, and nullable fields to ensure they match your usage patterns.
Copy TypeScript Output
Copy the generated types into your project for type-safe GraphQL queries and component props.
Use Cases
Frontend API Client Typing
Generate types matching your GraphQL queries for type-safe data access in React, Vue, or Angular components.
Schema-Driven Development
Generate TypeScript types from the GraphQL schema first, then implement resolvers and frontend code against those types.
API Documentation
Generate TypeScript types alongside GraphQL documentation to provide TypeScript-specific code examples for API consumers.
Type Validation for Testing
Use generated types to type-check mock data in tests, ensuring mock objects match the real GraphQL schema structure.
Pro Tips
Generate types from your actual production GraphQL schema, not a simplified local version — this catches field name and type mismatches.
For query result types, include only the fields your query selects — full schema types include fields you may not be fetching.
Prefer string literal unions over TypeScript enums for GraphQL enums — they work better with GraphQL code generators and are more ergonomic.
Re-generate types whenever the GraphQL schema changes. Stale types defeat the purpose of type safety.
Common Pitfalls
Assuming all fields are non-nullable in TypeScript types
Fix: GraphQL fields are nullable by default. Only fields marked with ! are non-null. Generated types must reflect nullable fields as Type | null.
Generating types once and never updating them
Fix: Add type generation to your build pipeline so types are always in sync with the schema. Stale types create a false sense of type safety.
Using the generated types for runtime validation
Fix: TypeScript types only exist at compile time. For runtime validation, use a library like zod or joi alongside the TypeScript types.
Frequently Asked Questions
QWhich GraphQL types are converted?
Object types, input types, enums, interfaces, unions, and scalar types are all converted to their TypeScript equivalents.
QHow are nullable fields handled?
Non-nullable fields (with !) become required properties. Nullable fields use TypeScript union with null or the optional (?) modifier.
QDoes it support custom scalars?
Common scalars like DateTime and JSON are mapped to appropriate TypeScript types. Unknown scalars default to any.
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