JSON to TypeScript
Generate readable TypeScript interfaces or type aliases from JSON objects and arrays.
JSON input
TypeScript output
Generated TypeScript will appear here.
Your data stays private
This tool runs directly in your browser. The content you enter is processed locally and is not sent to TechFixGen servers. No account or signup is required.
JSON to TypeScript guide
JSON stores values; TypeScript definitions describe their structure. Paste valid JSON, choose interfaces or type aliases, name the root type, and convert.
How inference works
Strings, numbers, booleans, and null map directly. Objects become named definitions, arrays infer element types, and mixed arrays use deterministic unions. Empty arrays become unknown[].
Nested types and limitations
Nested objects receive stable names derived from their property. Collisions get numeric suffixes. Inference describes the supplied sample only; it cannot discover optional fields or business rules absent from that JSON.
Privacy
JSON and generated definitions stay in your browser and are excluded from analytics.
JSON to TypeScript FAQ
Can it generate interfaces and aliases?
Yes. Select either output mode before converting.
How are null and mixed arrays handled?
Null remains null. Heterogeneous arrays become a conservative union of observed element types.
Are JSON values preserved?
No values are emitted; only structural type definitions are generated.
Is JSON uploaded?
No. Parsing and generation run locally.