JSON to TypeScript is now live on Tools.Town — paste a JSON sample and get clean, compile-ready TypeScript interfaces in seconds. No more hand-writing types for an API response and missing a field three levels deep.
What Does It Do?
Type Inference
Maps strings, numbers, booleans, null, objects, and arrays to their TypeScript equivalents.
Nested Aware
Generates a named interface for every nested object, to any depth.
Merge & Copy
Merges arrays of objects, marks optional keys, and copies straight to your clipboard.
Arrays of objects are merged: a key in every element is required, a key missing from any element becomes optional automatically.
How It Works
Paste JSON
Drop in a representative sample — the more cases it covers, the better the types.
Set options
Choose interface or type, root name, semicolons, and unknown-over-any.
Copy types
Copy the generated interfaces straight into your codebase.
Why We Built It
Typing JSON by hand is slow and error-prone, especially with deeply nested data. Generating types from a real sample gives you accurate, compile-ready interfaces instantly — so you spend time using the data, not describing it. Want the details on how inference handles edge cases like optionality and empty arrays? Read our guide to JSON-to-TypeScript type inference.
Try It Now
JSON to TypeScript
Turn any JSON sample into clean TypeScript interfaces — nested-aware, free, and in your browser.
Also in developer tools: JSON Formatter, JSON to YAML, and JSON Diff.
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Frequently Asked Questions
Does it handle nested objects and arrays?
Is my JSON uploaded anywhere?
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