Convert C++ structs/classes into JSON Schema and use the Mock Generator shortcut to create matching sample data.
Select which class/struct should be treated as the schema root.
Parsing runs entirely in your browser. Your source never leaves the page.
Paste your C++ headers to produce a JSON Schema instantly.
Supports public members, STL containers, nested structs, and default member values.
This online C++ 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 C++ source
Step 2 – Select the Root class or struct (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 C++ types and models 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 reads class/struct definitions with public members, typed fields, STL containers like std::vector/std::map, primitive types, and nested structs. Pointers and references are treated as optional fields so you can paste DTO headers or message objects directly.
Primitive types map to JSON strings/numbers/booleans. std::vector<T>, std::list<T>, arrays, and std::array become schema arrays, while std::map<string, T> becomes an object with additionalProperties. Unknown user-defined types fall back to strings unless a class with that name is also provided.
Yes. You can include using declarations, default member values, const qualifiers, and templates (for simple cases). Everything runs entirely inside your browser—no source code leaves your machine.
After the schema is generated, click "Generate Mock Data" to open the Mock Generator with the schema preloaded. Configure locales, array counts, and optional fields to instantly create example payloads.