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Avro to JSON Converter

Generate sample JSON data from Apache Avro schemas. Automatically creates example JSON objects that conform to your Avro schema definition, using default values where specified. Perfect for testing, documentation, and understanding schema structure.

Category: code
Use Case: Schema Testing, Documentation, Data Examples
Privacy: 100% browser-based

Recommended Settings

For Testing

  • Use default values in schema for realistic samples
  • Generated data conforms exactly to schema
  • Perfect for unit and integration tests

For Documentation

  • Include sample data in API docs
  • Help teams understand data structure
  • Generate examples for onboarding materials

Pro Tips

  • Add 'default' fields to your schema for custom sample values
  • Union types use the first non-null type for samples
  • Generated data is ready to use for testing and mocking

Most Popular

Most users generate sample JSON data for testing and documentation purposes

When to Use This Tool

Schema Testing

Generate sample JSON data to test your Avro schema before implementation. Quickly see what data structure the schema defines and validate field types and default values.

Recommended: Development

Documentation & Examples

Create example JSON data for API documentation, schema registry, or team onboarding. Sample data helps others understand the expected data structure without reading complex schema definitions.

Recommended: Documentation

Mock Data Generation

Generate sample data for testing applications that consume Avro-defined data. Useful for unit tests, integration tests, and development environments.

Recommended: Testing

How It Works

1

Paste your Avro schema definition

2

Tool analyzes field types and defaults

3

Generates sample JSON matching schema structure

4

Download or copy the sample data

100% Private

Files never leave your device. All processing happens locally in your browser.

Lightning Fast

Powered by Client-side JavaScript for optimal performance on modern browsers.

Open Source

Built with verified, open-source libraries. Fully transparent.

Frequently Asked Questions

What does this tool do?

This tool generates sample JSON data from your Avro schema. It reads the schema definition and creates example JSON objects that match the structure, using default values where specified or generating sample values for each field type.

How are sample values generated?

For fields with default values in the schema, those defaults are used. For other fields, the tool generates appropriate sample values based on type: strings get 'example_string', integers get 42, booleans get true, etc. Union types use the first non-null type.

Can I customize the sample values?

The tool automatically generates values based on the schema. To get specific values, you can add 'default' fields to your Avro schema definition, and those defaults will appear in the generated JSON. For full customization, manually edit the output after generation.

What happens with union types?

For union types (arrays of types like ['int', 'null']), the tool uses the first non-null type to generate a sample value. If you've specified a default value in the schema for that field, it will use the default instead.

Can I use this for testing?

Yes! The generated JSON data is perfect for unit tests, integration tests, mock data, API testing, and documentation examples. It conforms exactly to your Avro schema structure, making it ideal for validating schema-based applications.