JSON Formatter
Prettify and validate JSON with syntax highlighting.
JSON to TypeScript
Generate TypeScript interfaces from a JSON sample.
Runs locally in your browser. No data is sent to a server.
About JSON to TypeScript
Paste any JSON — object, array, or primitive — and instantly generate clean, idiomatic TypeScript interfaces or type aliases. Handles arbitrarily nested objects, arrays of objects, mixed arrays, optional fields (when a property is absent from some array items), and nullable values (when a value is null in some items). Everything runs locally in your browser; your JSON never leaves your machine.