JSON to TypeScript
Paste JSON and generate TypeScript interfaces in your browser — no upload, no signup.
Processed in your browser. Files never leave your device.
How it works
- Paste JSON or choose a
.jsonfile. - Optionally set a root interface name.
- Click Convert, then copy or download
types.ts.
Convert JSON to TypeScript interfaces in your browser
Developers often need TypeScript types from a live API response, a saved fixture, or a config blob. Structura’s JSON to TypeScript tool generates interfaces from that example locally—so you can move from sample data to usable types without pasting sensitive payloads into a hosted converter.
Ideal use cases include bootstrapping types for a new endpoint, documenting the shape of webhook bodies, turning QA fixtures into shared interfaces, and catching field drift when an API returns slightly different objects in an array. Because processing stays on your device, it is a better fit for client exports, internal services, and anything that might include emails, tokens, or account IDs.
What the tool produces
- TypeScript
interfacedeclarations inferred from objects and nested objects - Merged shapes for arrays of objects, with optional keys when a field is missing on some items
- Primitive handling for string, number, boolean, and null (including simple unions when samples differ)
- A customizable root name, plus copy and
types.tsdownload
Worked example
Input:
{"name":"Ada","active":true,"tags":["ops","data"]}
Keep the root name Root and click Convert. Output:
export interface Root { name: string; active: boolean; tags: string[]; }
For an array of objects where only some items include phone, Structura keeps
shared fields required and marks sparse fields optional—closer to how real API lists behave
than typing only from the first element.
Privacy, retention, and limits
Your JSON is not uploaded to Structura for conversion. Nothing is stored as a file on our servers; the work happens in the tab. We may record anonymous product analytics such as that a conversion ran and whether input came from paste or file—not filenames, contents, or outputs. Browser safety ceilings block inputs over about 5 MB. Circular structures are rejected with an error instead of hanging the page.
Supported input is JSON text or a .json file. The tool does not fetch URLs,
does not emit Zod or JSON Schema (use related tools below), and is free without an account.
Related tools: JSON → Zod · JSON Formatter · CSV → JSON
FAQ
Does my data get uploaded or stored?
No. Conversion and cleaning run entirely in your browser. Structura does not upload your paste or file for processing and does not retain file contents on a server. Closing the tab clears the in-memory copy.
Is processing private / local-only?
Yes for the tool’s job. Your payload stays on the device. Optional Cloudflare Web Analytics may record page views and anonymous events such as tool runs, paste vs file, and copy/download—never the contents of your JSON or CSV.
What size limits apply?
About 5 MB as a browser safety ceiling. Larger inputs may freeze or crash the tab depending on your device.
What formats are supported?
UTF-8 JSON objects and arrays (paste or .json file). Not JSON Lines, YAML, or XML. Circular structures are rejected.
Can I convert arrays of objects?
Yes. Keys present on every item are required; keys missing on some items become optional.
Is this the same as a JSON Schema generator?
No. This tool emits TypeScript interfaces from an example. For runtime validation, use JSON → Zod.
Do I need an account?
No. All Structura tools are free to use without signup.
Need a data tool we don’t have yet?
Tell us what you are trying to convert, clean, or validate. We are prioritizing tools based on real requests. Need JSON → Pydantic, Go structs, or SQL next?
Request a tool →