JSON Schema to Protobuf
proto3 messages from a JSON Schema: repeated fields, nested messages, enums from enum, oneof from oneOf/anyOf and map<string, …> from additionalProperties.
Frequently asked questions
Which JSON Schema features are supported?
$ref to #/definitions or #/$defs, required, enum, const, oneOf/anyOf (unions), allOf, nullable types (type: ["string","null"] or nullable: true), nested objects, arrays, additionalProperties maps and common formats. External $ref URLs are not fetched.
How are field numbers chosen?
In property order, starting at 1. Once a .proto is in use, never renumber fields — add new ones at the end.
Is JSON Schema to Protobuf free?
Yes. JSON Schema to Protobuf is free to use. You get 3 free conversions a day without an account, and unlimited use when you sign in with Google.
Are my files uploaded?
No. The conversion runs inside your browser, so your files stay on your device and are never sent to our servers.
Does it work on mobile?
Yes. PixKaro works in Chrome, Safari, Edge and Firefox on Android, iPhone, Windows and Mac.