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JSON to Protobuf (.proto) — Free & Private

Infer Protocol Buffers message definitions from JSON samples. Generates proto2 or proto3 schemas with nested messages, repeated fields, and snake_case naming — client-side only.

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JSON input
.proto output

About this tool

JSON→.protoproto2/3Nested messagessnake_caseDownload .proto

How to use

  1. Paste a representative JSON sample.
  2. Choose proto2 or proto3, package name, and field naming.
  3. Copy or download the generated .proto schema.

Examples

User object

{"id":1,"name":"Ada","tags":["admin"],"profile":{"city":"NYC"}}
syntax = "proto3";

message Root { … }
message Profile { … }

FAQ