About json2schema.app

Your Privacy-First JSON to Schema Converter

What is json2schema.app?

json2schema.app is a free, open-source tool that instantly converts your JSON data into type definitions and validation schemas for multiple programming languages. Built with developers in mind, our tool supports TypeScript interfaces, Python dataclasses, Java POJOs, Zod schemas, and GraphQL type definitions.

Whether you're building APIs, working with external data sources, or need to quickly generate type-safe code from JSON responses, json2schema.app streamlines your development workflow.

Why We Built This Tool

As developers, we often find ourselves working with JSON data from APIs, configuration files, and databases. Manually writing type definitions and schemas is time-consuming and error-prone. We created json2schema.app to solve this problem with a tool that:

  • Saves time: Generate schemas in seconds instead of writing them manually
  • Reduces errors: Automatically infer types from your JSON structure
  • Protects privacy: All processing happens in your browser - your data never leaves your device
  • Supports multiple languages: One tool for all your schema generation needs
  • Provides instant feedback: Real-time conversion with syntax highlighting

Key Features

100% Client-Side Processing

Your JSON data is processed entirely in your browser. We don't see, store, or transmit your data to any server.

Multiple Language Support

Generate TypeScript, Python, Java, Zod, and GraphQL schemas from a single JSON input.

Nested Object Support

Handles complex nested structures and automatically generates type definitions for nested objects.

Array Type Inference

Intelligently infers array types, including arrays of objects and union types for mixed arrays.

Syntax Highlighting

Beautiful syntax highlighting for both JSON input and generated schemas for better readability.

One-Click Copy

Instantly copy generated schemas to your clipboard and paste them into your project.

Supported Schema Types

TypeScript Interfaces

Generate type-safe TypeScript interfaces with proper type annotations. Perfect for frontend development, API clients, and ensuring type safety across your TypeScript projects.

Python Dataclasses

Create Python dataclasses with type hints. Ideal for API models, data processing, and working with JSON APIs in Python applications.

Java POJOs

Generate Java Plain Old Java Objects with private fields, getters, and setters. Perfect for Spring Boot applications, REST APIs, and enterprise Java development.

Zod Schemas

Create runtime validation schemas using Zod. Essential for form validation, API request validation, and ensuring data integrity in TypeScript applications.

GraphQL Type Definitions

Generate GraphQL schema definitions for your API. Useful for building GraphQL servers, defining types, and creating GraphQL schemas from existing JSON data.

Privacy & Security

Privacy is at the core of json2schema.app. Unlike many online tools that send your data to servers for processing:

  • No data upload: All JSON processing happens directly in your browser using JavaScript
  • No server-side processing: We don't have backend servers that handle your JSON data
  • No data storage: We never store or log your JSON input or generated schemas
  • Open source transparency: Our code runs in your browser where you can inspect it

This means you can safely use json2schema.app with sensitive data, proprietary APIs, and confidential information without worrying about data breaches or unauthorized access.

Use Cases

API Development

Quickly generate type definitions from API responses to create type-safe API clients.

Data Modeling

Convert sample data into structured data models for your application.

Code Migration

Migrate schemas between different languages and frameworks.

Documentation

Generate clear type definitions to document your API responses and data structures.

Prototyping

Rapidly prototype applications by generating schemas from example JSON data.

Learning

Educational tool for understanding how different languages represent data structures.

Technology Stack

json2schema.app is built with modern web technologies:

  • Vanilla JavaScript: No frameworks, just pure JavaScript for maximum performance
  • Tailwind CSS: Beautiful, responsive design with utility-first CSS
  • Client-side processing: All logic runs in the browser for privacy and speed
  • Syntax highlighting: Custom-built syntax highlighter for multiple languages

Free Forever

json2schema.app is completely free to use with no registration required. We support the tool through ethical advertising that respects your privacy. There are no premium plans, paywalls, or usage limits.

We believe developer tools should be accessible to everyone, from students learning to code to professionals building enterprise applications.

Future Development

We're continuously improving json2schema.app. Planned features include:

  • Additional language support (Rust, Go, C#, etc.)
  • Customizable naming conventions
  • Import/export schema configurations
  • Advanced type inference options
  • Schema validation and testing tools

Contact & Feedback

We'd love to hear from you! Whether you have suggestions, found a bug, or just want to share how you're using json2schema.app, please reach out through our contact page.