JSON to Go struct

In Go, decoding JSON into typed structs gives you compile-time safety and editor autocompletion, but writing struct definitions for a large API response by hand is slow and error-prone. This tool reads a sample JSON payload and generates matching Go structs with json tags, ready to paste into your code.

How to use it

1. Paste a representative JSON sample.
2. Copy the generated structs.
3. Rename the top-level struct and adjust types where the sample was ambiguous.

Example

Input (double quotes in real JSON):

{ 'id': 7, 'user_name': 'asha', 'active': true, 'tags': ['a', 'b'], 'address': { 'city': 'Pune' } }

Output:

type AutoGenerated struct {
	ID       int      `json:"id"`
	UserName string   `json:"user_name"`
	Active   bool     `json:"active"`
	Tags     []string `json:"tags"`
	Address  struct {
		City string `json:"city"`
	} `json:"address"`
}

How names and types are mapped

• Field names are converted to exported PascalCase, because encoding/json only fills exported fields. The original key is kept in the tag.
• Common initialisms follow Go style: id becomes ID, url becomes URL.
• Whole numbers become int, decimals become float64.

Review before using

• Nulls: a field that is null in the sample has an unknown type; choose a pointer type such as *string.
• Optional fields: add ,omitempty to tags for fields that may be absent when encoding.
• Large IDs: use int64, or string if the API sends IDs as strings.
• Timestamps: change ISO 8601 strings to time.Time.
• Extract nested anonymous structs into named types if you reuse them.