JSON to Protobuf Converter

About JSON to Protobuf Converter

Convert JSON data to Protocol Buffers (Protobuf) schema definition. Protocol Buffers is Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data.

Key Features

• Schema Generation: Automatically generates .proto schema from JSON structure
• Type Inference: Intelligently infers Protobuf types (int32, double, bool, string, repeated)
• Nested Support: Handles nested objects and arrays with message definitions
• Proto2 & Proto3: Support for both Protocol Buffers versions
• Customizable: Configure message name and package name
• File Upload: Upload JSON files directly or paste data
• Instant Preview: Real-time conversion as you type

How to Use

1. Input JSON Data: Paste your JSON data or upload a .json file
2. Configure Options: Select proto version, message name, and package
3. Review Output: The Protobuf schema updates automatically
4. Copy or Download: Use the Copy or Download button to save your .proto file

Example Conversion

JSON Input:

{
  "id": 12345,
  "name": "John Doe",
  "email": "john@example.com",
  "age": 28,
  "active": true,
  "roles": ["admin", "user"]
}

Protobuf Output:

syntax = "proto3";

package com.example;

message Message {
  int32 id = 1;
  string name = 2;
  string email = 3;
  int32 age = 4;
  bool active = 5;
  repeated string roles = 6;
}

Common Use Cases

• API Design: Generate Protobuf schemas for gRPC services
• Data Serialization: Convert JSON APIs to efficient binary format
• Microservices: Define service contracts and data structures
• Schema Evolution: Create versioned data schemas
• Cross-Platform: Generate code for multiple languages (Go, Java, Python, C++)

Protobuf Type Mapping

• String: JSON strings → string
• Integer: JSON integers → int32 or sint32
• Float: JSON decimals → double
• Boolean: JSON booleans → bool
• Array: JSON arrays → repeated type
• Object: JSON objects → nested message

Proto2 vs Proto3

• Proto2: Uses optional/required/repeated keywords, supports default values
• Proto3: Simpler syntax, all fields are optional by default, no required keyword
• Recommendation: Use proto3 for new projects (default)

Compiling Protobuf

After generating your .proto file, compile it using the Protocol Buffers compiler:

# For Go
protoc --go_out=. message.proto

# For Java
protoc --java_out=. message.proto

# For Python
protoc --python_out=. message.proto

# For C++
protoc --cpp_out=. message.proto

Privacy & Security

All conversions happen locally in your browser. Your JSON data is never uploaded to any server, ensuring complete privacy and security.