JSON to TypeScript Online
Instantly convert JSON to TypeScript online with our powerful TypeGen tool.
// Your typescript code will appear here... // Select a target language above.
Built With Care
“TypeGen regenerates output on every keystroke, so the schema, interface, or struct is always derived from the current JSON — there is no stale conversion step to forget. Nested structures map recursively, and field naming follows common conventions for each target (camelCase for TypeScript, json tags for Go).”
What is TypeGen?
TypeGen is an advanced online tool designed to convert JSON objects into clean, production-ready types and schemas. Whether you're a frontend developer working with TypeScript, a backend engineer using Go, or need validation with Zod, TypeGen automates the tedious process of manual type definition. The output regenerates on every keystroke, and because conversion runs in your browser, large API payloads with customer data never cross the network.
- 1Paste or type your JSON data into the 'JSON Input' area.
- 2Select your desired target language from the dropdown (TypeScript, Zod, or Go).
- 3The tool instantly generates the corresponding code in the output panel.
- 4Click 'Copy Code' to copy the generated output to your clipboard.
- 5Press 'Load Sample' first to see how nested objects and arrays get named, then replace it with your own payload.
- 6When the 'Invalid JSON' badge appears, run the input through the JSON formatter to fix trailing commas and unquoted keys, then paste the cleaned version back.
- TypeScript InterfacesGenerate nested TypeScript interfaces with proper naming conventions and type inference.
- Zod Schema ValidationCreate Zod schemas for runtime validation, including inferred types for your application.
- Go StructsConvert JSON to Go structs with appropriate json tags, supporting nested objects and arrays.
- Instant Type ConversionInstant Type Detection: Automatically identifies and converts JavaScript, JSON, TypeScript, and more.
- Live Re-GenerationOutput updates on every keystroke and whenever you switch the target language, so there is no convert button to forget.
What is TypeGen? Specs
Limits
- 3 output targets: TypeScript, Zod, Go structs
- JSON input must be a flat object
Formats
- Output: copy-paste type definition
Defaults
- Sample JSON prefilled
How it works
- Plain JS object traversal
Honest caveats
- Nested arrays become any[] — not deeply typed
- No enum or union inference — all unions collapse to string
Real Ways People Use This
API Response Typing
Paste a sample JSON response from a REST API and instantly generate TypeScript interfaces for your frontend data models.
Form Validation Setup
Convert a JSON object representing form fields into a Zod schema for runtime validation with inferred TypeScript types.
Go Backend Structs
Generate Go structs with proper JSON tags from API payloads, saving time when building Go microservices.
Database Migration Helpers
Convert a sample document from MongoDB or CouchDB into TypeScript or Go types before writing your schema migration.
Unit Test Fixtures
Turn sample API responses into typed fixtures so mock data in tests matches the interfaces the code under test actually imports.
SDK Documentation Snippets
Generate current types from the latest response shape and embed them directly into client-library README files and doc pages.
- Arrays with mixed types or empty arrays generate 'any[]' — provide a populated sample for accurate type inference.
- Generated interface names are derived from JSON keys. Ambiguous keys like 'data' or 'result' may produce generic names that need manual renaming.
- Nested objects deeper than 5 levels are supported but may produce lengthy type definitions. Consider flattening very deep structures.
- 1Validate the input JSON first — the 'Invalid JSON' badge means the output does not reflect your payload.
- 2Compare generated names against your API contract when nesting is deep.
- 3Run the generated code through a compiler once before committing it.