quicktype is a code generator that produces strongly-typed models and serializers from JSON, JSON Schema, TypeScript, and GraphQL queries across multiple programming languages.
The tool solves the problem of manually writing type definitions and serialization code when working with JSON data. It accepts JSON samples, JSON Schema definitions, TypeScript types, or GraphQL queries as input and automatically infers the structure to generate corresponding type definitions and converters. This approach eliminates the tedious and error-prone work of hand-coding types that match JSON structures, allowing developers to move directly from data specification to type-safe code.
quicktype suits projects where developers need to consume JSON APIs or work with JSON data across different programming languages. The tool is particularly valuable in polyglot environments where a single API response must be consumed by services written in multiple languages. It supports a broad range of target languages including TypeScript, Python, Go, Rust, Java, C#, Swift, Kotlin, and many others, making it applicable whether you are building web services, mobile applications, or backend systems. The web interface at app.quicktype.io provides an interactive way to experiment with type generation, and the tool also offers a command-line interface and Node.js packages for integration into build workflows.
The project maintains active development with regular updates to support new language targets and input formats. The codebase is written in TypeScript and accepts contributions for implementing additional language generators. The tool is available both as a browser-based application that processes data locally without sending it over the internet, and as installable packages for developers who prefer command-line or programmatic access.
