JSON to TypeScript Interface Generator

Paste JSON and instantly generate TypeScript interfaces. Recursively handles nested objects, arrays, union types, and nullable fields. 100% client-side.

Root Interface Name:

JSON Input

TypeScript Output

About JSON to TypeScript Conversion

This tool analyzes the structure of your JSON data and generates corresponding TypeScript interfaces. It recursively processes nested objects and detects array element types to produce accurate, ready-to-use type definitions.

Features

Recursively generates interfaces for nested objects
Detects array element types (primitives, objects, mixed)
Handles null values as any (nullable)
Converts JSON keys to valid TypeScript property names
Custom root interface naming

How It Works

Primitive values map to string, number, or boolean
Nested objects generate separate named interfaces
Arrays of objects generate item interfaces (e.g., ITagsItem)
Null values become any since the type cannot be inferred

Related Tools

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JSON Schema Validator — validate JSON against a schema
JSON to YAML — convert between JSON and YAML
JSON Diff — compare two JSON documents