Convert Protocol Buffers (.proto) to JSON & Schema

Parse proto3 message definitions into mock JSON payloads or Draft-07 JSON Schema specifications.

Protobuf (.proto) to JSON Schema Converter

Parse Protocol Buffer (proto3) message definitions into mock JSON data or JSON Schema specifications.

Protocol Buffer (.proto) Definition

Conversion Target

Generated Mock JSON Object

{
  "id": 1001,
  "username": "sample_username",
  "email": "sample_email",
  "is_active": true,
  "reputation_score": 99.5,
  "tags": [
    "sample_tag"
  ]
}

About This Tool

Protobuf to JSON Schema Converter parses Protocol Buffer (proto3) message definitions, extracting field tags, scalar types, and repeated fields to generate mock JSON objects or Draft-07 JSON Schema specifications.

Key Features

Parses proto3 message { ... } syntax and field tags

Outputs either mock JSON data or Draft-07 JSON Schema

Maps int32, int64, float, double, bool, string, and repeated fields

How to Use This Tool

Paste your .proto message definition into the input editor.
Select conversion target: Sample Mock JSON Payload or Draft-07 JSON Schema.
Copy the generated output.

Why Use This Tool

Quickly generate sample REST JSON payloads for testing gRPC-to-JSON gateways.
Generate standard JSON Schema validation files directly from protobuf contracts.

Pro Tips

Use Mock JSON mode to quickly test API endpoints before your gRPC services are fully deployed

Frequently Asked Questions

How are repeated fields handled in Protobuf conversion?

Repeated proto fields are automatically mapped to JSON arrays ([ ... ]) containing sample elements of the designated scalar type.

Related Tools

API Mock Payload & Fake Data Generator

Generate mock JSON REST API responses for Users, Products, and Paginated datasets.

Linux Chmod Permissions Calculator

Calculate Linux/Unix file permissions visually with octal numbers and symbolic notation.

Cron Expression Descriptor

Convert cron expressions into human-readable text.