JSON to TypeScript Converter – because typing by hand is tedious
I built a small tool to save time: JSON to TypeScript Converter.
You paste JSON, and it gives you TypeScript interfaces—immediately. That’s it. No setup, no config, no login.
We’ve all been there: you get a JSON response from an API, and now you need types. So you read through the structure, check nested objects, guess types based on values, and write it all by hand. Then the API changes, and you do it again.
This tool speeds that up. Paste the JSON, and it generates clean, readable interfaces with proper type inference—string, number, boolean, unions where needed (like "active" | "inactive"), and optional properties when values are null. Nested objects become nested interfaces. Arrays are typed accordingly.
It handles edge cases reasonably: mixed types, optional fields, and arrays with consistent structures. It won’t be perfect for every use case (especially if your JSON is wildly inconsistent), but it’s a solid starting point—90% there, so you can focus on the 10%.
It’s free to use for basic conversions. There’s also a Pro tier ($9/month) that adds:
- Support for multiple interfaces (from JSON with multiple root-level objects)
- Optional field detection with nullability analysis
- Export as
.tsfile - No rate limits
I use it daily. I made it public because I figured others might save a few minutes here and there too.
No tracking. No ads. Open in a tab, use it, close it.
Try it here:
👉 https://tool-json-to-typescript-converter.vercel.app
Feedback? Issues? GitHub repo is public — open an issue or PR.
Sometimes the best tools are the boring ones that just do one thing and get out of your way. This is one of them.
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