Protocol Buffers (Protobuf) to JSON Schema Visualizer
Decode proto3 & proto2 definitions into readable JSON objects, Draft-07 schemas, and TypeScript interfaces without installing protoc. Fast, secure, and executed entirely in your local browser memory.
Protocol Buffers (Proto3) vs. JSON Schema Mapping Guide
Google Protocol Buffers (Protobuf) is a language-neutral, platform-neutral binary serialization format. Modern distributed architectures often require bridging gRPC and Protobuf service schemas into RESTful JSON APIs, OpenAPI / Swagger specifications, and TypeScript client typings.
| Protobuf Type | JSON Schema Type | TypeScript Type | Canonical JSON Representation |
|---|---|---|---|
| string | "string" | string | UTF-8 character string |
| int32, uint32, sint32 | "integer" | number | Regular numeric integer (e.g., 42) |
| int64, uint64, sint64 | ["string", "integer"] | string | number | Encoded as string (e.g., "1000000000") to prevent JS 53-bit IEEE 754 precision loss |
| float, double | "number" | number | IEEE 754 floating point number |
| bool | "boolean" | boolean | true or false |
| bytes | "string" (contentEncoding: "base64") | Uint8Array | string | Standard Base64 string with padding |
| google.protobuf.Timestamp | "string" (format: "date-time") | string | Date | RFC 3339 UTC string (e.g., "2026-10-11T21:00:00Z") |
| google.protobuf.FieldMask | "string" | string | Comma-delimited string of field names |
| repeated T | "array" (items: T) | T[] | JSON array of elements |
| map<K, V> | "object" (additionalProperties: V) | Record<string, V> | Key-value JSON mapping |
Do I need to install protoc or any compiler?
No. This visualizer features a complete in-browser tokenizer and recursive descent parser that parses Proto3 and Proto2 grammars client-side. You do not need to download the Google Protocol Buffer compiler or any binary dependencies.
Is my proprietary .proto file uploaded to any server?
Never. In accordance with the ToolsAA Privacy-First architecture, 100% of the lexical parsing, AST generation, schema transformations, and mock syntheses occur inside your web browser. No data leaves your machine.
Why are field names camelCase in the JSON Schema?
According to the official Google Protobuf JSON Mapping specification, field names default to lowerCamelCase in JSON representations (unless overridden by the [json_name = "..."] field option). You can toggle between camelCase and snake_case using the toolbar switch.
Can I use this with gRPC and Connect RPC services?
Yes. The tool inspects all service and rpc definitions, extracts streaming flags, and generates idiomatic TypeScript client signatures and Draft-07 request/response object definitions.