JSON to TypeScript — free online tool
You've got a chunk of JSON from an API, and now you need to write TypeScript types for it by hand. For a big, nested object that's slow and easy to get wrong. We added a free tool that does it for you — JSON to TypeScript — right in your browser.
What it does
Paste any JSON and it instantly generates matching TypeScript interfaces or type aliases. Nested objects are handled too, so a deep structure turns into clean, ready-to-use types you can drop straight into your code.
Nothing leaves your device
The whole thing runs in your browser. Your JSON is never uploaded to a server and nothing is saved anywhere. When you close the tab, it's gone. That means you can safely paste real data from your own projects.
How to use it
- Open JSON to TypeScript and paste your JSON into the box.
- Pick whether you want interfaces or type aliases.
- Copy the generated TypeScript and paste it into your project.
It's free with no limit. There are more small tools on the Apps page.