JSON to Protobuf Converter
Infer a proto3 schema (.proto) from a JSON sample — fields, types, and nested messages.
Types are inferred from values: string, int32/double, bool, nested objects become nested messages, and arrays become repeated fields. Field names are snake_cased and numbered. Null or empty arrays produce a best-effort guess with a warning — review and tighten the schema before shipping.
About this tool
JSON to Protobuf Converter runs entirely in your browser on DevTools — no signup, no upload.
What this tool does not do
- JSON to Protobuf Converter is a free in-browser utility, not a hosted API, and keeps no server-side history.
How to use this tool
Using JSON to Protobuf Converter
Open JSON to Protobuf Converter, enter or paste your input, and copy the result.
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