Free online JSON to TypeScript interface tool, auto-generate interface and type, supports nested objects and arrays
TL;DR: Free JSON to TypeScript interface tool. Auto-generate interface and type with smart type inference, supports nested objects and arrays.
This tool runs entirely in your browser. Open DevTools → Network panel and search your input — it appears in no request.
FAQ
Completely free, no registration or login required. Convert JSON to TypeScript interfaces directly in your browser — all parsing runs locally with no usage limits.
Yes. It correctly recognizes nested objects, arrays, and element types within arrays, automatically inferring interfaces while preserving the hierarchy.
No. All conversion runs locally in your browser. Your data is never sent to any server, ensuring complete privacy.
Related Tools
Related Articles
JSON to TypeScript: Complete Guide to Auto-Generating Type Definitions
Step-by-step tutorial on how to quickly convert JSON data to TypeScript interfaces and type definitions, boosting development efficiency and code quality
Best Online JSON Formatter Tools Comparison (2026)
Comparing 5 popular online JSON formatter tools across features, speed, privacy, and pricing. DevToolkit Pro stands out with local processing, Unicode safety, and free unlimited use.
Online XML/JSON Converter: Convert Between Data Formats
Learn how to convert between XML and JSON formats. Understand the differences between XML and JSON, and use cases in API integration, configuration management, and data exchange.