SYS.TOOLS

JSON to TypeScript

Free JSON to TypeScript converter — paste JSON and instantly get TypeScript interfaces. Handles nested objects, arrays, and all primitive types. Runs locally in your browser.

JSON to TypeScriptType GeneratorDeveloper Tool
TypeScript
FREQUENTLY ASKED QUESTIONS
How does the JSON to TypeScript conversion work?
The tool parses your JSON and recursively generates TypeScript interfaces. Objects become interfaces, arrays infer their element type, and primitives map to string, number, boolean, or null.
Does it handle nested objects and arrays?
Yes. Nested objects generate separate named interfaces (named after their key), and arrays infer the type from the first element.
Is the conversion done locally?
Yes, 100% client-side. Your JSON never leaves your browser — there is no API call. The conversion happens instantly as you type.
Can I use the generated types in my project?
Absolutely. Click the copy button and paste the interfaces directly into your TypeScript project. You may want to rename the root interface to match your domain.