Convert Java POJOs/DTOs/records into JSON Schema. Use the quick Mock Generator shortcut to create matching sample JSON without leaving the page.
Select which class should be treated as the root when generating the schema.
Parsing runs entirely in your browser. Your source never leaves the page.
Paste your Java classes to produce a JSON Schema instantly.
Supports collections, nested objects, Maps, and popular annotations.
This online Java class to JSON Schema converter helps you generate JSON Schema from real models (DTOs, structs, and classes) so you can validate payloads, share contracts, and generate mock JSON.
Step 1 – Paste your Java source
Step 2 – Select the Root class (if needed)
Step 3 – Review the JSON Schema output
definitions and $ref when your models reference other models.Step 4 – Validate or generate mock JSON
anyOf/oneOf/allOf), verify the result with a full validator like Ajv.Schema keyword support note
Generated schemas can include $ref and may be edited to include anyOf, oneOf, or allOf. For complex schemas, use a full JSON Schema validator and dereference before mock generation if needed.
Use these tools to validate schemas, generate mock payloads, format JSON examples, and keep code and contracts in sync.
Generate example JSON from your schema for testing, fixtures, and documentation.
Validate JSON against common schema keywords and find mismatches quickly.
Generate strongly-typed Java POJOs from JSON samples.
Build schema from representative JSON samples to complement model-first schemas.
Explore schema examples and patterns for objects, arrays, enums, and constraints.
Clean up JSON examples before validating against schema or sharing docs.
The converter understands common POJOs, Lombok data classes, records, builders, and DTOs that contain nested objects, generics, arrays, Lists/Sets, and Maps. It reads annotations like @JsonProperty, @SerializedName, @JsonInclude, and nullable hints to keep naming and optionality aligned with your serialization framework.
Primitive wrappers (Integer, Double, Boolean, etc.), Java time types, enums, Optionals, and generic collections all map to their closest JSON Schema equivalents. When type information is missing (for example, raw List fields without generics) we warn you and fall back to reasonable defaults so the schema remains valid.
After the schema is generated, click "Generate Mock Data" to open the Mock Generator with your schema preloaded. From there you can configure locales, array counts, and instantly create realistic sample payloads.
Open the settings panel and select any parsed class from the dropdown. By default we pick the first public class, but you can switch to nested classes or DTOs declared later in the file at any time without reloading the page.