Santekno/tools
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JSON → TypeScript

Generate TypeScript interfaces (or type aliases) from JSON. Infers nested structures and array element types.

Processed in your browserUpdated · Jan 2026
Input
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Output
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How to use JSON → TypeScript

Paste your input on the left, choose the options you want, and the output appears instantly on the right. Everything runs in your browser — none of your data is sent to a server.

  • Paste or type your input in the INPUT panel
  • The output regenerates automatically as you type
  • Use Copy to put the result in your clipboard
  • Click Sample to load a working example

What is JSON → TypeScript?

JSON → TypeScript walks your JSON and emits one TypeScript interface per object shape (PascalCase named after the parent key). Arrays infer their element type from the first element; heterogeneous arrays trigger an inline warning. Switch the toggle to emit `type X = { … }` aliases instead of `interface X { … }`. Useful for bootstrapping types from API responses or fixture data — paste-ready output that compiles in any TS project. This tool is part of santekno's developer toolbox — a curated collection of utilities built for engineers who care about speed, privacy, and simplicity.

Common use cases

  • Debugging API payloads and integration issues
  • Inspecting tokens, hashes, or encoded strings during development
  • Generating fixtures and sample data for tests
  • Sharing readable output with teammates in code reviews

FAQ

From the first element. If subsequent elements have different shapes, the tool emits a `// ⚠ heterogeneous array detected` warning at the top.