About this tool
Go structs are the idiomatic way to model JSON in Go: each exported field carries a `json:"..."` struct tag that the standard `encoding/json` package uses to marshal and unmarshal data. This converter parses a JSON sample, infers a Go type for every value — `int` for whole numbers, `float64` for decimals, `string`, `bool`, `interface{}` for null or unknown, and `[]T` for arrays — and emits PascalCase exported field names while keeping the original key in the tag. Arrays of objects are merged into a single shape so the generated struct includes every key seen across the elements.
Use it to scaffold request and response types for an HTTP API, model a config file or webhook payload, or turn a sample document from a NoSQL store into typed structs you can paste straight into your package. Name the root struct, toggle `,omitempty` on the tags, and choose between separate named types for nested objects or inline anonymous structs — handy for quick one-off models versus reusable shared types.
Everything runs client-side in your browser — your JSON is parsed locally and never sent to a server.
Frequently asked questions
How are JSON types mapped to Go types?
Whole numbers become `int`, decimals become `float64`, strings become `string`, booleans become `bool`, and `null` (or anything unknown) becomes `interface{}`. Arrays become a Go slice `[]T` of the element type, and nested objects become named structs (or inline anonymous structs if you toggle that on).
Why are my field names like user_id turned into UserID?
Go exports fields that start with an uppercase letter, so keys are converted to PascalCase. Common initialisms — ID, URL, API, HTTP — are kept fully upper-cased to follow golint conventions, so `user_id` becomes `UserID` and `api_url` becomes `APIURL`. The original key is preserved in the json struct tag.
What does the omitempty option do?
Adding `,omitempty` to a struct tag tells `encoding/json` to leave that field out of the marshaled JSON when it holds its zero value (0, "", false, nil, or an empty slice/map). It only affects encoding, not decoding.