JSON to TypeScript Interface Generator
Generate strongly typed TypeScript interfaces and type aliases from sample JSON documents instantly.
Batch workspace
Format multiple files locally in one run.
How to use the JSON to TypeScript
Paste code or file
Paste your raw JSON text or upload directly.
Configure options
Choose indentation, dialect, or formatting preferences.
Format & export
Click format, then copy, download, or inspect in tree view.
What is a JSON to TypeScript?
Generate strongly typed TypeScript interfaces and type aliases from sample JSON documents instantly. This tool re-indents and organizes code according to standard style conventions while checking for syntax validity. Everything executes 100% inside your browser, guaranteeing zero latency and complete privacy for API keys, user tokens, and confidential database schemas.
Options Explained
| Option | Description |
|---|---|
| Root Type Name | The name assigned to the top-level TypeScript interface or type alias. |
| Declaration Style | Choose whether to declare TypeScript types as `interface` or `type` aliases. |
| Make all fields optional (?) | Appends `?` to all property keys to model partial API responses. |
Frequently Asked Questions
How does JSON to TypeScript handle nested objects?
Nested objects are extracted into separate, strongly typed child interfaces with clean PascalCase naming.
Can I generate `type` aliases instead of `interface` declarations?
Yes. Switch the Declaration Style option to 'type Root = {...}' in the options panel.
How are JSON arrays typed?
Array element types are inferred. If an array contains multiple primitive types, union types (e.g. `(string | number)[]`) are generated.
Is my JSON payload uploaded to any server?
No. All type generation is executed 100% locally in your browser memory.
Can I make all generated fields optional?
Yes. Check 'Make all fields optional (?)' in the options panel to append `?` modifiers.
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