About JSON → TypeScript
Convert JSON to TypeScript interfaces online without uploading sample payloads. Paste API responses and get typed shapes — including nested objects as separate interfaces when needed. Ideal for bootstrapping types from real JSON while keeping private response bodies on your device.
What stays local: API sample JSON used to generate types.
What you can do with JSON → TypeScript
- JSON → TypeScript interfaces
- Nested object type extraction
- Copy-ready type output
- Local-only conversion
How to use JSON → TypeScript
- Paste JSON. Paste a sample JSON object or array.
- Generate types. Convert to TypeScript interfaces.
- Copy into your project. Paste the generated types into your codebase and refine names.
Examples
Simple object
Input
{"id":1,"name":"Ada"}Output
interface Root {
id: number;
name: string;
}Privacy
What stays local: API sample JSON used to generate types. DevTooKit is local-first — no signup wall, no server-side processing for this tool, and no watermark on results.
Related tools
FAQ — JSON → TypeScript
Privacy, offline use, and how this free online tool works.
Does conversion upload my JSON?
No. Type generation runs in your browser.
Are nested objects supported?
Yes — nested objects can be emitted as separate types for cleaner interfaces.
Is it free?
Yes — free JSON to TypeScript conversion with no account.