Protobuf to TOON Converter

Example: Protobuf input and real TOON output

The output below was generated by the same conversion code the converter uses, run on this sample when the page was built.

user {
  id: 42
  email: "dev@example.com"
  active: true
  roles: "admin"
  roles: "billing"
  profile {
    display_name: "Dev Ops"
    locale: "en-SE"
  }
}

user:
  id: 42
  email: dev@example.com
  active: true
  roles[2]: admin,billing
  profile:
    display_name: Dev Ops
    locale: en-SE

TOON output is 15% smaller than the Protobuf input. The same data is 140 characters as minified JSON and 218 as pretty-printed JSON. Sizes are character counts, not tokens: token counts depend on the model's tokenizer (see the tokenizer comparison). Across larger datasets, TOON averages about 43% fewer tokens than JSON (42.6%) according to the official TOON benchmark.

Protobuf to TOON: what changes

• Reading Protobuf: Input is Protobuf text format (the readable form used in .textproto files and debug output), not the binary wire format. Repeated fields are collected into arrays; no .proto schema is read, so types are inferred from the values.
• Writing TOON: TOON saves the most on arrays of objects that share the same fields: they collapse into one header plus one row per record. Nested or non-uniform objects are written as indented key: value lines and save much less.

Why Convert Protobuf to TOON?

Use TOON when building LLM-powered applications, optimizing API costs, or when you need compact, readable data for AI models.