Click Generate to create TypeScript interfaces and Zod schemas
Related Tutorials
What is JSON to TypeScript & Zod Schema Generator?
This tool converts JSON data into TypeScript interfaces (or type definitions) and Zod validation schemas. TypeScript interfaces provide compile-time type safety, while Zod schemas add runtime validation - together they give you end-to-end type safety from API responses to your frontend code. This is particularly useful when working with REST APIs where you need to ensure your TypeScript types match the actual API response structure.
How to Use
- Paste your JSON data (object or array of objects) into the input field
- Set your preferred interface name (e.g., User, Product, Order)
- Choose output mode: TypeScript only, Zod only, or both
- Configure options: use type vs interface, optional fields, export keyword, z.coerce
- Click Generate to create the code
- Copy or download the generated TypeScript file
Why Use This Tool?
Tips & Best Practices
- Use 'Load Sample' to see how the tool handles nested objects and arrays
- Enable 'Make all fields optional' for API responses that may have partial data
- Use z.coerce when your API returns numbers as strings (e.g., query params)
- For arrays, only the first item is used to infer the item type
- Combine with z.infer<typeof MySchema> to derive types from Zod schemas
- Export the generated code directly into your TypeScript project
Frequently Asked Questions
How do I convert JSON to TypeScript interface?
Paste your JSON data into the input field, set your preferred interface name, and click Generate. The tool will automatically infer types from the JSON values and generate a TypeScript interface with proper type annotations for each field.
What is the difference between TypeScript interface and Zod schema?
TypeScript interfaces provide compile-time type checking in your IDE and during build. Zod schemas provide runtime validation - they can check if data actually matches the expected shape at runtime. Using both together gives you end-to-end type safety.
Can I derive TypeScript types from Zod schemas?
Yes! Use z.infer<typeof MySchema> to derive TypeScript types from your Zod schema. This way you only need to maintain the Zod schema, and TypeScript types are automatically inferred. Example: type User = z.infer<typeof UserSchema>.
What is z.coerce in Zod?
z.coerce automatically transforms input values before validation. For example, z.coerce.number() will convert string '42' to number 42. This is useful when dealing with API responses or form inputs where numbers might be returned as strings.
Does this tool handle nested JSON objects?
Yes, the tool recursively processes nested objects and arrays. Each nested object gets its own interface or type definition, and arrays of objects generate separate item interfaces. The output is properly ordered with dependencies first.
Why should I use Zod instead of just TypeScript interfaces?
TypeScript interfaces are erased at runtime - they don't validate actual data. If an API returns unexpected data, your TypeScript types won't catch it. Zod validates data at runtime, catching malformed API responses, invalid form inputs, and other data issues that TypeScript can't detect.