Is my JSON uploaded to Convertr?

No. JSON parsing and TypeScript generation run in JavaScript in your browser. Pasted content and generated code are not uploaded or stored.

Can this handle arrays of objects?

Yes. Arrays of objects are merged into a shared item type. Missing and nullable fields are represented conservatively.

What happens with empty arrays or null-only fields?

Empty arrays become unknown[] and null-only values become null, so the generated output stays honest about ambiguous examples.

Does it create interfaces or type aliases?

Both modes are available. Interface mode emits named interfaces for objects, while type alias mode emits named aliases.

JSON to TypeScript Generator

Paste example JSON or an API response and generate readable TypeScript without uploading data.

Input JSON

0 bytes

TypeScript output

TypeScript appears here. Everything runs in your browser.

Ready

Generator options

Root type name Output mode Optional nullable fields Mark missing or nullable object fields as optional while keeping null in the type. Readonly properties Prefix generated object properties with readonly.

Parsing uses JSON.parse on this page, then inference, copy and download happen locally. Analytics only use size, depth, root kind, mode and failure buckets.

Nested API responses

Objects and arrays are inferred recursively, including arrays of nested objects and repeated response items.

Conservative ambiguous types

Mixed primitive arrays become unions, empty arrays become unknown[], and null-only values stay null.

Safe property names

Invalid TypeScript identifiers are emitted as quoted keys, so API fields with spaces or hyphens still compile.

Related developer tools

JSON Formatter

Format, validate and minify JSON

JSON Schema Validator

Validate JSON contracts

JSON to CSV Converter

Flatten JSON into CSV

JSON to XML Converter

Convert JSON into XML

XML to JSON Converter

Convert XML into JSON

Developer Tools

More browser-native utilities

Nested API responses

Conservative ambiguous types

Safe property names

Related developer tools

Settings