What is JSON to Go Struct Converter?
JSON to Go Struct Converter is a free online tool that transforms JSON data into idiomatic Go struct definitions with proper type inference and json tags. When building Go applications that consume JSON APIs, you need matching struct definitions for unmarshaling. Manually writing these structs is tedious, especially for deeply nested responses with dozens of fields. This tool automates the entire process by parsing your JSON and generating production-ready Go code in milliseconds. It infers the correct Go types for each field including string, int, float64, bool, and time.Time for ISO 8601 date strings.
How to Use This Tool
Paste your JSON into the input area or load the sample data to see how it works. Set a custom root struct name if needed. Choose between "Separate" mode (each nested object becomes its own named struct) or "Inline" mode (nested objects are defined inline within the parent struct). The Go struct output updates automatically as you type. Copy the generated code and paste it directly into your Go source files. The tool also shows stats including the number of structs and fields generated.
Common Use Cases
- Generating struct definitions from API responses when building Go HTTP clients
- Scaffolding data models from JSON configuration files or database exports
- Converting JSON schema examples into Go types for request and response handling
- Quickly prototyping Go data structures from sample JSON payloads during development
Why Use a Client-Side Tool?
All JSON parsing and Go code generation happens entirely in your browser. Your API responses and data structures are never sent to any server, which is critical when working with production API data, internal endpoints, or sensitive business logic. There are no usage limits, no account requirements, and the tool works offline after the page loads. Your data stays on your device from start to finish.
Frequently Asked Questions
How does the tool handle null values in JSON?
Null values are converted to pointer types (*interface) in the generated Go struct. This allows the field to represent both the absence of a value (nil) and the presence of data. For more specific typing, you can manually change the pointer type after generation based on your knowledge of the API.
What is the difference between Separate and Inline struct modes?
Separate mode creates a named type definition for each nested object, making structs reusable across your codebase. Inline mode nests anonymous structs directly within the parent, keeping everything in a single type definition. Separate is better for large projects with shared types, while Inline is convenient for one-off API responses.
Does the tool detect time.Time fields automatically?
Yes. The converter recognizes ISO 8601 date strings (like "2024-01-15T10:30:00Z") and maps them to Go's time.Time type. When a time.Time field is detected, the tool automatically includes the required import statement for the "time" package at the top of the generated code.