JSON to TypeScript Converter – Paste JSON, Get Interfaces
If you work with APIs or config files, you’ve probably spent time manually writing TypeScript interfaces to match JSON structures. I built JSON to TypeScript Converter to cut that down to seconds.
The tool does one thing: you paste JSON, and it generates clean, readable TypeScript interfaces. That’s it. No account needed. No data stored. Just input and output.
You can try it here:
👉 https://tool-json-to-typescript-converter.vercel.app
It handles nested objects, arrays, optional fields (based on null values), and basic type inference. The output is formatted with Prettier, so it’s ready to drop into your codebase.
There’s a free tier that covers most use cases. You can convert up to 50KB of JSON at once, and there are no usage limits. It’s enough for daily use, whether you’re prototyping or integrating third-party APIs.
For heavier needs, there’s a Pro tier at $9/month. It increases the payload limit to 500KB, adds support for multiple interfaces from array samples, and lets you customize naming (like PascalCase vs camelCase). No credit card is required to try the free version.
I built this because existing tools either overcomplicated things or broke on edge cases (looking at you, deeply nested arrays with mixed types). This one aims to be predictable. If your JSON has a null value, the field becomes optional. If it sees a number that’s always an integer, it uses number — no false assumptions about id being number and age being string.
It’s open-source (link in the footer), and I welcome feedback or issues on GitHub. No analytics, no tracking — just a small tool that saves a few minutes here and there.
If you’re tired of writing the same interfaces by hand, give it a try.
Top comments (0)