JSON to TypeScript
🔒 In your browserGenerate TypeScript interfaces from JSON.
export interface Root {
id: number;
name: string;
tags: string[];
active: boolean;
address: Address;
}
export interface Address {
city: string;
}Arrays of objects are merged into a single interface. Adjust optionality (?) by hand if fields can be missing.
About the JSON to TypeScript
Writing TypeScript interfaces by hand from an API response is tedious. This free JSON to TypeScript converter reads a JSON sample and generates matching TypeScript interfaces — including nested objects and arrays — so you get type safety in seconds.
It runs in your browser, so your JSON never leaves your machine.
How to generate TypeScript from JSON
- Paste a representative JSON sample (ideally a real API response).
- Get ready-to-paste TypeScript interfaces with inferred types.
- Nested objects become their own interfaces; arrays are typed from their items.
Why generate types from JSON
Hand-writing TypeScript interfaces to match an API response is tedious and error-prone, and they drift out of sync as the API changes. Generating them from a real sample gives you accurate types in seconds — including nested objects and arrays — so you get autocompletion and compile-time safety when consuming the data. Re-generate whenever the response shape changes.
Frequently asked questions
How does JSON to TypeScript conversion work?
The tool infers the type of each field from your JSON sample — strings, numbers, booleans, arrays and nested objects — and writes corresponding TypeScript interfaces.
Will it handle nested objects and arrays?
Yes. Nested objects are turned into separate named interfaces and arrays are typed from their element structure.
Is my JSON uploaded?
No. Conversion happens entirely in your browser, so your data stays private.
How does it handle nested objects and arrays?
Nested objects become their own named interfaces, and arrays are typed from their element structure, so the generated types mirror the full shape of your JSON.
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Copy this and paste it into your page's HTML. The tool runs in the visitor's browser, just like here. Change height to fit, or add the optional auto-resize snippet below. Add ?theme=dark to the URL for dark mode.
<iframe src="https://toolhq.dev/embed/json-to-typescript/" title="JSON to TypeScript — ToolsHub" width="100%" height="520" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" loading="lazy"></iframe>Optional: auto-resize the iframe height
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<script>
addEventListener("message", function (e) {
if (e.data && e.data.type === "toolshub:resize") {
document.querySelectorAll('iframe[src*="/embed/"]').forEach(function (f) {
if (f.contentWindow === e.source) f.style.height = e.data.height + "px";
});
}
});
</script>