JSON to Types — Code Generator
Generate TypeScript, Go, Python, Rust, C#, Java, Kotlin, and Swift type definitions from JSON. 100% client-side.
What is JSON to TypeScript Conversion?
Converting JSON to typed definitions is essential for modern software development. When you receive data from an API, having accurate type definitions ensures type safety, better IDE autocomplete, and fewer runtime errors. This tool analyzes your JSON structure and generates idiomatic type definitions for 8 popular programming languages.
The type inference engine recursively analyzes your JSON data to detect strings, numbers (distinguishing integers from floats), booleans, dates (ISO 8601), arrays, nested objects, and nullable fields. It also recognizes common patterns like email addresses, UUIDs, and URLs, adding helpful comments to your generated code.
Supported Languages
TypeScript interfaces provide compile-time type checking for JavaScript applications. Go structs with json tags enable seamless JSON marshaling. Python dataclasses offer clean, modern data structures. Rust structs with serde derive macros enable safe serialization. C# classes with JsonPropertyName attributes work with System.Text.Json. Java classes with Jackson annotations are standard for enterprise APIs. Kotlin data classes provide concise, immutable data holders. Swift structs with Codable conformance enable native JSON decoding.
Common use cases include generating types from API responses for frontend development, creating data models for backend services, documenting API schemas, bootstrapping new projects with accurate type definitions, and converting between different type systems when porting code between languages.
Frequently Asked Questions
Paste your JSON into the input field, select TypeScript from the language tabs, and the tool will automatically generate TypeScript interfaces with proper types, optional fields, and nested object support.
Yes. Paste your API response JSON, select Go, and the tool generates Go structs with proper json tags, exported field names in PascalCase, and pointer types for optional fields.
When processing arrays of objects, the engine compares all objects to detect which fields appear in some but not all entries. Missing fields are marked as optional (? in TypeScript, *pointer in Go, Optional in Python, Option in Rust).