How to use: Choose input format (JSON or XML), paste your data in the left textarea, pick a target language, and click Convert (or just type — auto-converts on input).
Batch merge: Paste multiple JSON objects (newline-separated or array) to automatically merge fields from all samples for richer type inference.
Enum detection: String fields with 2–10 distinct values are auto-detected as enums and shown in the stats panel. JSON Schema output includes enum constraints.
Naming style: Override language defaults with Auto (language convention), camelCase, PascalCase, or snake_case.
TypeScript: Generates interface definitions with proper types, optional markers (?), and array types.
Python: Generates @dataclass classes with full type hints (List, Optional).
Go: Generates struct definitions with json:"key" tags and exported field names.
Java: Generates POJOs with @JsonProperty annotations and getter/setter methods.
C#: Generates classes with [JsonPropertyName] attributes and auto-properties.
Swift: Generates Codable structs with CodingKeys enum when needed.
Kotlin: Generates data class with Jackson @JsonProperty annotations. Fields default to null. Arrays use List<T>. Nullable types use ? suffix.
Rust: Generates struct with #[derive(Debug, Clone, Serialize, Deserialize)] and #[serde(rename)] attributes. Fields in snake_case. Optional uses Option<T>. Arrays use Vec<T>.
Dart: Generates class with manual fromJson()/toJson() methods. Field names in camelCase. Nullable fields use ?. Arrays use List<T>.
JSON Schema: Generates JSON Schema (Draft 7) with $schema, definitions, and $ref references. Includes required arrays and enum constraints for detected enums.
Ruby: Generates Ruby classes with attr_accessor, initialize, self.from_json, and to_json. Field names in snake_case.
C++: Generates C++ struct with nlohmann/jsonto_json() and static from_json() methods. Uses std::shared_ptr, std::vector, field names in snake_case.
XML input: Parsed into JSON-like structure first. Repeated elements become arrays, nested elements become objects, empty elements become null. Attributes inferred as typed fields.
Från exempeldata till typdefinitioner
En klass, struct eller ett gränssnitt är ett kontrakt vid kompilering: fältnamn plus typer. Att generera en från exempeldata är inferens, inte sanning — ett fält som saknas i exemplet är okänt, inte frånvarande; ett värde som ses en gång som 2 blir ett heltal även om 2.5 dyker upp senare. Slå ihop flera exempel för rikare inferens och granska sedan valfrihet och enums för hand.
