CodesBeautify

JSON to Go Struct Generator

Generate Go structs with json tags from a JSON sample, one struct per nested object.

JSON
Go
Runs locally in your browser

About the JSON to Go Struct Generator

Go decodes JSON into structs whose exported field names are matched to keys through struct tags. Writing those tags by hand for a large payload is where typos creep in. This generator derives them: each key becomes an exported PascalCase field with a json:"key" tag holding the original name, and each nested object becomes its own named struct.

Types follow the encoding/json defaults: string, bool, float64 for decimals, int64 for whole numbers, slices for arrays and interface{} for nulls. Fields are emitted with tab indentation so gofmt leaves them unchanged.

The generator does not add omitempty or pointer types, because whether a field may be absent is not visible in a single sample. Add them where the API documents optional fields. Time values arrive as strings; change the type to time.Time if the format is RFC 3339.

How to use

  1. Paste a JSON sample on the left and name the root struct.
  2. Copy the structs into a Go file in your package.
  3. Decode with json.Unmarshal(data, &root).

Common questions

Why int64 rather than int?
JSON numbers can exceed 32 bits, and int64 is safe on every platform. Change to int where you know the range.
How do I make a field optional?
Use a pointer type and add ,omitempty to the tag, for example *string \`json:"nickname,omitempty"\`.
Are nested structs inlined or separate?
Separate named structs, which keeps them reusable and readable. Inline them by hand if you prefer.