Protobuf decoder

Developer tools

Loading tool

The tool is loaded only when you open it.

All processing for this tool happens in your browser. Your input is not sent to a server.

About this tool

Paste or open Protobuf binary, Hex, or Base64 data to inspect field numbers, Wire types, and values locally. Add a .proto Schema to show field names and nested messages.

Common uses

Inspect Protobuf fields from logs, message queues, or network captures
Check binary message structure without uploading the data

How to use it

1.Paste Base64 or Hex data, or choose a binary file
2.Optionally paste or choose a .proto Schema and select the root message
3.Decode the data to inspect fields, raw bytes, and JSON output

Limits and notes

Without a Schema, the tool can reliably show field numbers, Wire types, and raw values; Schema support covers common message fields and is not a full protoc compiler.
The tool does not call remote services and limits input to 5 MB.

Frequently asked questions

Is my data uploaded?

No. Decoding happens in this browser, and binary data or Schema is not sent to a server.

Can I decode without a .proto file?

Yes. The tool still reads field numbers, Wire types, offsets, and raw values; a Schema makes the result easier to read.