Consuming a JSON API in Go
Paste a sample response and get the struct with json tags ready for encoding/json to decode into.
JSON to Go Struct
Generate Go structs from a JSON sample in your browser, complete with json struct tags.
Maintained by Roshan.
Use JSON to Go Struct
Converts json sample to go struct in this tab, with nothing sent anywhere.
Runs entirely on your deviceThe conversion happens in this browser tab. Nothing you type is uploaded, logged or stored, which is worth knowing for anything you would not paste into a search box.
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Browse all generatorsAbout JSON to Go Struct
Go's static typing means consuming a JSON API starts with declaring a struct that matches it, and doing that by hand is fiddly - every field needs both an exported Go name and a json tag mapping it back to the original key. Generating the struct from a sample handles both at once: paste the JSON, get the struct with its tags already written. This infers the shape recursively, giving each nested object its own struct, and applies Go's conventions automatically - exported PascalCase field names paired with json tags carrying the original lower-case keys, so encoding and decoding round-trip correctly. The result is a working struct you can paste into a Go file and refine, rather than a skeleton you fill in field by field.
Using JSON to Go Struct
- The JSON is parsed and its structure inferred recursively.
- Each field gets an exported PascalCase Go name and a json tag preserving the original key, so decoding matches the source.
- Nested objects become their own named structs, referenced by the parent.
- JSON numbers map to float64, the safe default for arbitrary JSON numbers; narrow to int where you know the data.
- Arrays become slices of the inferred element type.
Where json to go struct helps
Modelling a config file
Generate the struct from an example config, then narrow numeric types and mark optional fields.
Before you use the result
- Numbers become float64, since JSON does not distinguish integers. Change to int or int64 where the field is always whole.
- A single sample cannot prove optionality; Go handles missing fields with zero values, but pointer types for genuinely optional fields are yours to add.
- A null value maps to interface{}, which you may want to replace with a concrete pointer type.
- Field names are derived from keys; unusual keys are cleaned into valid identifiers.
- The output is a starting point to refine, not a complete contract.
Questions about JSON to Go Struct
Are json tags included?
Yes. Every field carries a json tag with the original key, so decoding round-trips correctly.
Why is every number a float64?
JSON has one number type. float64 is the safe default; narrow to int where you know the value is whole.
Does it handle nested objects?
Yes. Each becomes its own named struct referenced by the parent.
What about optional fields?
Go uses zero values for missing fields. Add pointer types yourself where a field is genuinely optional.
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