JSON to TypeScript
Generate TypeScript interfaces or Zod schemas from a JSON sample.
Processed locally in your browser. Nothing you enter is uploaded or stored.
- Generates nested `interface` declarations, or nested Zod schemas, from one representative sample.
- Zod output gives you runtime validation, not just compile-time types — check a payload actually matches the shape you expect, not just tell TypeScript it does.
- Name the root type and get sensibly named child types.
- Runs in your browser; the sample isn't uploaded.
Why this is private
- Processed locally in your browser. Nothing you enter is uploaded or stored.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Infers TypeScript interfaces, or Zod runtime-validation schemas, from a sample JSON value — a fast starting point for typing an API response instead of writing types by hand.
How to use it
- 1Paste a representative JSON sample.
- 2Optionally name the root type.
- 3Pick TypeScript or Zod schema output.
- 4Copy the generated code.
Tips
- Since it's inferred from one sample, optional fields or fields that can be multiple types in your real data won't be detected — review the output before relying on it for a large API. This applies to both TypeScript and Zod output.
Frequently asked questions
What people use it for
Type a third-party API responsePaste a real response and get interfaces to drop into your client code.
Validate an API response at runtimeGenerate a Zod schema and call `.parse()` on incoming data instead of trusting a compile-time-only type.
Bootstrap types for a fixtureTurn a JSON test fixture into the types your code should expect.
Document an endpoint's shapeShare generated interfaces or schemas as a quick contract with teammates.
Related guides
- How to read JSON with a tree viewerA tree viewer turns a wall of brackets into a structure you can expand, search and copy paths from. Here's how to use one effectively.
- JSON parse errors explained: 'Unexpected token', 'Expected comma or brace', and the restWhat each common JSON error message actually means, the usual cause, and how to find the spot fast using line and column.
- How to format JSON (and actually understand the errors)JSON looks like a JavaScript object but follows stricter rules. Here's what those rules are and how to read the errors when they're broken.
Related tools
All developer toolsJSON Schema GeneratorGenerate a JSON Schema from a sample JSON document, with a toggle for the required-fields default.JSON Viewer & FormatterView, format, validate, edit and beautify JSON with an interactive tree view, plus a shareable link.JSON ValidatorValidate JSON syntax and pinpoint errors instantly.JSON MinifierStrip whitespace to compress JSON to its smallest size.
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JSON to TypeScript