JSON to Go Struct Converter

How JSON maps to Go types

The tool reads the top-level keys of a JSON object and writes one struct field per key. Types come from the sample values you paste:

• number becomes float64, boolean becomes bool and string becomes string.
• null, arrays and nested objects become interface{}.
• Field names are capitalized so they are exported, and each field gets a json tag with the original key.

JSON to Go example

Input:

{"id":1,"name":"Ada","active":true,"address":{"city":"London"},"tags":["math"]}

// Go output
type Root struct {
    Id float64 `json:"id"`
    Name string `json:"name"`
    Active bool `json:"active"`
    Address interface{} `json:"address"`
    Tags interface{} `json:"tags"`
}

What to review before you use the Go output

• Paste a JSON object, not a bare array. The tool walks the top-level keys, so an array root produces meaningless index names.
• Nested objects and arrays are not expanded into their own types. In the example, address and tags both fall back to a generic type, so write those types by hand.
• One sample cannot show which fields are optional or which numbers are integers. Numbers are always mapped to a floating-point type.
• The json tags let encoding/json match keys correctly even after capitalization. Run gofmt on the result to align the fields.
• Replace interface{} with real struct or slice types for nested data.

Related: JSON to Java, JSON to TypeScript, JSON Formatter, JSON Validator