JSON to TypeScript Converter
Generate TypeScript interfaces from JSON data. Runs entirely in your browser.
About the JSON to TypeScript Converter — Generate TS Interfaces from JSON
TypeScript adoption is at an all-time high, and every modern frontend or Node.js project needs typed interfaces for API responses. Manually writing interfaces for deeply nested JSON is tedious and error-prone. This converter parses your JSON, infers types for every field — including nested objects, arrays of objects, mixed-type arrays, and null values — and generates clean, ready-to-use TypeScript interfaces. Each nested object gets its own named interface for modularity. The converter runs entirely in your browser, so it is safe to paste production API responses, internal data structures, and any JSON you cannot share with a hosted service.
Common use cases
- Generate TypeScript interfaces from REST API responses
- Convert JSON config files to typed interfaces
- Type GraphQL query results for frontend consumption
- Create types for database query results in Node.js
- Bootstrap type definitions for new TypeScript projects
Why client-side?
Every byte you paste, type, or upload here is processed entirely inside your browser. Nothing is sent to a server, logged, or stored. That means it's safe to use this tool on production secrets, customer data, internal logs, and any input you would not paste into a hosted SaaS formatter.
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Frequently Asked Questions
- How do I convert JSON to TypeScript?
- Paste your JSON into the input field, set a root interface name, and click Convert. The tool instantly generates TypeScript interfaces with proper type inference for all fields.
- Does it support nested objects and arrays?
- Yes. Nested objects become separate named interfaces, and arrays of objects generate typed array interfaces. Mixed-type arrays produce union types.
- Is this JSON to TypeScript converter private?
- Yes. All conversion happens locally in your browser. Your JSON data is never sent to any server, making it safe for sensitive API responses and internal data.
- Can I customize the interface names?
- Yes. You can set a custom root interface name, and nested interfaces are automatically named based on their property keys using PascalCase.