Data Formats

Protobuf to JSON Converter

Free online Protocol Buffers (Protobuf) to JSON converter. Encode JSON to Protobuf binary and decode Protobuf binary back to JSON. Paste your .proto schema and data. No sign-up required.

Free to use No sign-up Runs in your browser

Tool workspace

What Is Protocol Buffers (Protobuf)?

Protocol Buffers (Protobuf) is a language-neutral, platform-neutral, extensible mechanism for serializing structured data, developed by Google. It is used extensively in gRPC APIs, inter-service communication, and data storage. Protobuf uses a schema (.proto file) to define message structures, and data is serialized into a compact binary format that is smaller and faster to parse than JSON or XML.

How to Use This Protobuf Converter

  1. 1Paste your .proto schema definition in the schema input area.
  2. 2The tool automatically parses the schema and lists available message types.
  3. 3Select the message type you want to encode or decode.
  4. 4To encode: Paste JSON data and click Encode to Protobuf to get hex and Base64 output.
  5. 5To decode: Paste hex bytes or Base64 encoded protobuf binary and click Decode to JSON.

Common Use Cases

Debug gRPC Services

Decode protobuf binary responses from gRPC services to readable JSON for debugging.

Test Protobuf Schemas

Validate that your .proto schema correctly encodes and decodes sample data.

Inspect Binary Payloads

Decode protobuf-encoded messages captured from network traffic or logs.

Frequently asked questions

Which Protobuf versions are supported?

This tool supports both proto2 and proto3 syntax. Most modern APIs use proto3.

Can I decode without a schema?

A schema is required to correctly decode protobuf binary data, as the binary format does not include field names or types. Without a schema, the tool cannot determine the structure of the data.