JSON → Type Schema
Paste JSON and instantly generate type definitions for TypeScript, Python, Go, Rust, Java, C#, Swift, and Kotlin.
Paste JSON on the left to generate a TypeScript interface.
Paste JSON on the left to generate a Python dataclass.
Paste JSON on the left to generate a Go struct.
Paste JSON on the left to generate a Rust struct.
Paste JSON on the left to generate a Java record.
Paste JSON on the left to generate a C# record.
Paste JSON on the left to generate a Swift struct.
Paste JSON on the left to generate a Kotlin data class.
How to use the JSON to Types
- Paste a JSON sample, for example an API response.
- Choose TypeScript, Python, Go, Rust, Java, C#, Swift or Kotlin.
- Copy the generated types into your project.
Why use this JSON to Types
- Generate TypeScript interfaces from JSON
- Python dataclasses, Go structs, Rust serde structs
- Nested objects become named types
- Runs locally
Related tools
JSON to Type Schema Generator — FAQ
What languages are supported?
TypeScript interfaces, Python dataclasses, Go structs with JSON tags, Rust structs with serde derives, Java records, C# records, Swift Codable structs, and Kotlin data classes.
Does it handle nested objects and arrays?
Yes. Nested objects generate additional named types. Arrays infer the element type from the first element.
Is my data sent anywhere?
No. All processing happens entirely in your browser using JavaScript. Nothing is uploaded.
What happens with null values?
Null values produce optional or nullable types depending on the target language — optional in TypeScript, Optional in Python, a pointer in Go, and Option in Rust.
How do I convert a JSON API response to a TypeScript interface?
Paste your API response JSON into the input, select TypeScript, and click Generate. The tool infers every field's type and outputs a ready-to-use interface block you can copy straight into your project.
Can the tool handle a root-level JSON array?
Yes. Paste an array such as [{"id":1,"name":"Alice"}] and the generator uses the first element to infer the item type, producing a typed array or slice definition in the target language.
What happens with mixed-type arrays?
Mixed arrays (e.g. [1, "two", null]) produce a union type in TypeScript (number | string | null), Any in Python, interface{} in Go, and serde_json::Value in Rust.
How do I convert JSON to a Go struct with json tags?
Select Go from the language dropdown and click Generate. Each JSON key becomes a struct field with its inferred type and a json:"..." tag, ready to paste directly into your Go source file.
Does the tool work offline?
Yes. All conversion logic runs entirely in your browser. Once the page has loaded, you can generate types without an internet connection.
Are field names converted to language conventions?
JSON key names are used as-is for most languages. Go fields are PascalCased with automatic json:"..." tags. You can rename fields in your editor after generating.
What does the tool do with deeply nested JSON objects?
Each nested object becomes its own named type. The parent type references child types by name, keeping the generated code flat and readable at every nesting depth.
Can I use the generated code directly in my project?
Yes — the output is valid, copy-pasteable code. For TypeScript you may want to add export. For Python the dataclasses import is included. Minor tweaks like renaming the root type are common.
Does it generate Zod schemas or JSON Schema?
Not currently. The tool generates language-native type definitions (interfaces, structs, dataclasses). Zod and JSON Schema output may be added in the future.