JSON to Go Struct Converter

Strings map to string, booleans to bool, integers to int (or int64 for large values exceeding 32-bit range), decimals to float64, null to interface{}, arrays to typed slices (e.g., []string, []int), and nested objects to separate Go structs. Empty arrays become []interface{} since the element type cannot be inferred.

Separate structs (the default) create a named type for each nested object — for example, type Address struct {...} — making them reusable and testable across your codebase. Inline structs embed the definition directly in the parent field (e.g., Address struct { City string }), which is more compact but cannot be reused elsewhere.

When enabled, json tags include "omitempty" (e.g., `json:"name,omitempty"`). This tells Go's JSON encoder to skip fields with zero values (empty strings, 0, false, nil) when marshaling to JSON. This is particularly useful for PATCH request bodies, optional API fields, or any case where you want to distinguish between "not set" and "set to zero".

JSON keys are converted to PascalCase for exported Go fields following Go conventions. snake_case (user_name becomes UserName), kebab-case (user-name becomes UserName), and camelCase (userName becomes UserName) are all handled correctly. The original JSON key is always preserved in the json struct tag to ensure correct serialization.

Yes! If your JSON root is an array, the tool uses the first element to infer the struct type. The generated struct represents a single element — use []StructName in your Go code to unmarshal the full array. For example: var items []Item; json.Unmarshal(data, &items).

Fields with null values are mapped to interface{} since the actual type cannot be determined from null alone. If other objects in an array have non-null values for the same field, the tool will infer the type from those values. For production code, you may want to use pointer types (*string, *int) for nullable fields.

The tool generates json struct tags only. To add GORM tags (gorm:"column:name"), sqlx tags (db:"name"), or other annotations, copy the generated structs and add the additional tags manually. The struct structure and field types will still save you significant time.

Yes. The generated code is plain Go that uses only the standard library encoding/json package. It works with any Go version (1.13+) and any module setup. Just paste the structs into a .go file in your project and start using them immediately.

Each level of nesting produces a separate named struct type. For example, a JSON object with user.address.coordinates would generate three structs: Root, Address, and Coordinates. This keeps the code clean and each type independently usable. With inline mode, all nesting is embedded in the parent struct instead.