Protocol Buffers message workbench

What it does

Decode binary Protocol Buffers messages or encode validated JSON with a supplied schema.

How to use it

1. Supply a proto schema and message name; choose JSON encoding or hexadecimal decoding.
2. Processing stays in your browser. No upload or sign-up.

Example

Person with name Ada and age 36 encodes to 0a 03 41 64 61 10 24.

Methodology

Bundled protobuf.js parses supplied schema strings, resolves only supplied imports, verifies messages and encodes or decodes in a terminable worker.

Limitations

100,000 schema characters, 20 supplied imports/200,000 combined characters, 100 KB message and 1 million output characters. Use decimal strings for 64-bit integers. Unknown binary fields are omitted from readable output. No fetched imports, gRPC, account or network connection.

Automation

This tool runs in your browser. No upload API or MCP endpoint is available.