Paste or Load a Sample

Copy a .proto file from your repo, your gRPC server, or a public vendor schema, and paste it into the editor on the left. If you want to see the viewer in action first, click Sample to load a small e-commerce schema with messages, an enum, and a few nested types.

syntax = "proto3";

message Order {
  string id = 1;
  Customer customer = 2;
  repeated LineItem items = 3;
  OrderStatus status = 4;
}

If the schema has syntax errors, you'll see a message under the editor pointing at the line where the parser gave up.

Browse the Messages

The right side re-renders instantly whenever your input changes. Each top-level message shows up as its own row with a fields column — expand it and you see name, type, number, and rule for every declared field. Nested messages and enums get their own rows, so you can follow a chain like Order → Customer → Address visually. The schema reading follows the rules in the proto3 language spec.

Filter and Reorient

Every column has a filter box. Type string in the type column to see only string fields, repeated in the rule column to spot all the lists, OrderStatus in the type column to find every reference to a particular enum. Use Main or Nested to flip orientation when a message has more fields than messages — sometimes it's easier to read fields as rows and messages as columns.

Go Full Screen for Big Schemas

For schemas with 20+ messages — the kind that come out of a busy gRPC service or a vendor SDK — hit Full Screen. The table expands to the full viewport so you can scroll through dozens of messages without the editor pane in the way.

Export When You're Done

Need to walk a non-developer through the schema, or paste it into a design doc? Hit Excel to download the rendered table as .xls, openable in Excel, Google Sheets, or LibreOffice Calc. Parsing happens client-side using a small handwritten .proto parser — nothing is uploaded.