JSON to Crystal Class
JSON Tools
Convert a JSON sample into a reviewable Crystal data model.
Parameters
Input
Output
Auto-calculate
0 characters · 0 bytesUse cases
When to use JSON to Crystal Class
Convert a JSON sample into a reviewable Crystal data model.
1Bootstrap a Crystal model from an API response
2Create an initial type for a webhook or configuration payload
3Compare generated Crystal fields with an existing domain model
4Compare JSON structures across development, staging, and production APIs
5Prepare reproducible JSON payloads for API documentation, bug reports, or test cases
6Generate Schemas, language models, Excel workbooks, or Postman requests from JSON samples
7Review duplicate keys, nulls, field types, and contract changes before release
Guidance
Get reliable results
- 1Use a representative JSON sample with every important field
- 2Review nullability, unions and business types in the generated Crystal model
- 3Rename generated types and fields to match project conventions
The generator infers Crystal structure from observed JSON values and cannot infer business enums, runtime validation or fields missing from the sample.