Convert JSON to Protobuf

Convert JSON to Protobuf builds a .proto schema from a flat JSON object. The Convert JSON to Protobuf tool gives you instant output with type inference, live preview, and export options.

Paste your input above or import a file below.
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Supported file types: .json, .txt
Total characters: 0

How to Use:

  1. Paste a flat JSON object into the Input JSON box for example:
    { "name": "Alice", "age": 30, "email": "[email protected]" }
  2. Or use the Choose File button to import a .json or .txt file.
  3. The output updates instantly with a basic .proto schema under Protobuf Output.
  4. Click Copy Output to copy the schema, or Export to File to download it as message.proto.
  5. Use Clear All to reset everything.

What this tool can do:

It takes a basic JSON object and generates a simple Protocol Buffers schema. Field names are preserved, types are inferred (e.g., string, int32, float, bool), and fields are auto-numbered. It doesn’t use an external schema or descriptor it builds a fresh .proto template from your data, instantly. You’ll see output flash on change, plus get a character count below the result.

Example:

Input:

{ "id": 1, "name": "Alice", "active": true }

Output:

syntax = "proto3";

message MyMessage {
  int32 id = 1;
  string name = 2;
  bool active = 3;
}

Common Use Cases:

If you’re prototyping Protobuf messages from sample data or need a .proto to match a known JSON structure, this tool helps you skip boilerplate. It’s great for documentation, mock services, or quickly scaffolding schema files without writing them manually. All output is client-side and instant.

Useful Tools & Suggestions:

Before converting, Validate JSON makes sure the structure is solid and won’t cause issues mid-process. Then, if you’re comparing formats or debugging, Convert Protobuf to JSON can be used to flip it back and double-check the round-trip.

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