JSON to Go Struct Converter

Turn a JSON example into a Go type starting point

Paste a representative JSON value to create Go type declarations with field tags. Objects become struct fields, arrays become slice-shaped types, and nested values are reflected in the generated type structure. The JSON keys in tags preserve the names expected by the source data while Go field names are made usable as exported identifiers.

This is sample-based generation: the example describes only values that appeared in that sample. It is not a schema editor and cannot infer every optional field, alternate response shape, or business rule. The JSON format itself allows objects, arrays, strings, numbers, booleans, and null values, so include realistic examples of the shapes your application receives. RFC 8259 defines those JSON value kinds; the Go encoding/json documentation explains how Go values and field tags participate in JSON encoding and decoding.

What the generated declarations contain

A JSON key such as user_name can be represented as a Go field such as UserName with a json:"user_name" tag. Nested objects add nested struct shapes, while arrays use slice types. The default root type name is Root and the default package is main; both can be changed to fit the file you plan to use. By default the output includes JSON tags and does not add omitempty.

Type inference follows observed sample values. A number may be emitted as an integer or a floating-point type depending on the value; nulls and fields with varying types deserve particular review. A generated declaration is a useful first pass for an API response model, fixture, or JSON configuration structure.

Generate and refine the Go output

1. Paste valid JSON

   Use a complete object or array that includes the nested fields you need. Check commas, quotation marks, brackets, and braces if no output appears.

2. Name the root type

   Replace Root with a project-specific name such as AccountResponse. In Go options, choose the package name that belongs in the destination file.

3. Select field tags

   Choose JSON tags for JSON decoding, YAML tags for YAML use, or both when the same struct is used with both formats. Turn on omitempty only when omitting empty values during JSON encoding is intended.

4. Review and copy or download

   Inspect the field names, nested types, tags, and numeric types. Copy the declarations or download the Go file, then compile and exercise it with representative payloads in your project.

Keep the example close to real responses

If an API field can be both a string and a number, or can be null in some responses, test those variants separately and adjust the type manually. Include arrays with representative elements: an empty array alone does not show what element type the API may return. For endpoints with multiple response envelopes, generate from each shape or define a shared type deliberately.

Questions about inferred Go types

Verify the type against the actual contract

Generated code is inferred from sample values and is not compiled or tested against your API. Confirm numeric ranges, null handling, missing keys, arrays, and fields whose types vary. A pointer or a more general type may be appropriate for a nullable or mixed field, but choose that from the real data contract and the behavior your application needs. Review tags and package declarations before adding the output to a production project.

When omitempty is enabled, check the destination behavior carefully: zero values such as false, 0, or an empty string may be omitted by some Go JSON encoding semantics. Keep it disabled if the receiver must distinguish an explicitly present empty value from an absent field.