How are types inferred?

Each JSON value is mapped to a TypeScript type: strings, numbers, and booleans by value; arrays by their element type; and objects to nested interfaces. Null values become optional/nullable where detected.

Can it handle nested objects?

Yes. Nested objects generate their own named interfaces, and arrays of objects infer a shared element interface, producing clean, reusable types.

JSON to TypeScript Types

Paste a JSON object or API response and instantly generate matching TypeScript interfaces — including nested objects and arrays. Speeds up typing API data.

Files never leave your browser

Root interface name

JSON Input

How to use JSON to TypeScript Types

Convert JSON to TypeScript interfaces online. Infers types, nested objects, and arrays automatically. Free, private JSON-to-TS generator in your browser.

Open JSON to TypeScript Types using the tool above — no sign-up needed
Enter your data or upload a file (processed entirely in your browser)
Click the action button and get your result instantly
Copy to clipboard or download your result

Your data never leaves your device — 100% private processing.

Frequently Asked Questions

Free · No spam

Get weekly tool tips & updates

New tools, power-user tips, and productivity hacks — delivered free every Friday.

No spam, ever. Unsubscribe with one click.

Why use JSON to TypeScript Types?

No installation — use directly from any browser
Handles large inputs without crashing or timeouts
Syntax highlighting and formatted output for readability
Copy to clipboard shortcut for fast workflow integration

Common use cases

Validate and format JSON responses from APIs
Encode/decode Base64 strings during debugging
Generate UUIDs for database seeds or test data
Minify CSS or JavaScript before deployment
Diff two code snippets to spot regressions

Related Developer Tools

JSON Formatter & Validator

Format, validate, and minify JSON instantly. Includes syntax highlighting, error detection, and a collapsible tree view — free, private, in-browser.

JSON to CSV Converter

Convert JSON arrays to CSV format online. Supports nested objects, custom delimiters, and CSV to JSON conversion. Free and private.

YAML ↔ JSON Converter

Convert YAML to JSON and JSON to YAML online. Validate syntax instantly with error messages. Free, private converter that runs in your browser.

Regex Tester

Test and debug regular expressions online. See live matches, capture groups, and replace output. Free, private, instant.

Base64 Encoder & Decoder

Encode text or files to Base64, or decode Base64 strings back to text. Fast, free, and runs entirely in your browser.

URL Encoder / Decoder

Encode and decode URLs and URL components online. Convert special characters to percent-encoding and back instantly — free, private, and fast.

Explore all Developer Tools.