About TypeScript Interface Generator

Generate TypeScript interfaces from JSON data. Part of the DevTools Surf developer suite. Browse more tools in the Generators collection.

Use Cases

• Generating type-safe interfaces from REST API response samples
• Creating TypeScript types for third-party API integrations
• Bootstrapping type definitions for JSON configuration files
• Converting JSON fixture data into reusable interface contracts

Tips

• Paste a JSON API response to generate matching interfaces
• Review optional fields and adjust nullability as needed
• Use the output as a starting point for strict type definitions

Fun Facts

• TypeScript was created by Anders Hejlsberg at Microsoft and publicly released on October 1, 2012, as version 0.8.
• Anders Hejlsberg also created Turbo Pascal and was the lead architect of C#, making him one of the most influential language designers.
• TypeScript became the 4th most popular language on GitHub by 2023, up from 10th place in 2017.

FAQ

Output: interface or type alias?

Toggle between both. Interfaces support declaration merging; type aliases support unions and mapped types. Pick per project convention.

Does it detect optional fields?

Fields missing from any sample record become `?:` (optional). Always-present fields are required. Verify the output with a fuller sample set.

What about discriminated unions?

Not auto-detected. For JSON with a 'type' field discriminator, you'll need to manually combine the generated interfaces into a union.

How is this different from json-to-typescript-types?

Same core engine; this tool's output always uses `interface`. json-to-typescript-types has more output options (types, Zod schemas). Use either; the output is equivalent.