REST vs gRPC

What gRPC is

gRPC is a high-performance RPC framework built on HTTP/2. It uses Protocol Buffers (binary serialization) and strongly defined service contracts.

Protocol differences

• REST: HTTP + JSON (text-based).
• gRPC: HTTP/2 + Protobuf (binary).

Performance and latency

Binary serialization and HTTP/2 multiplexing make gRPC efficient for low-latency, high-throughput internal communication.

Streaming

• REST: usually request-response model.
• gRPC: supports client streaming, server streaming, and bidirectional streaming natively.

Contracts

gRPC services are defined in .proto files. These definitions generate strongly-typed client and server code in multiple languages.

Example (conceptual)

service UserService {
  rpc GetUser (UserRequest) returns (UserResponse);
}

When gRPC wins

• Internal microservice communication.
• Low latency requirements.
• Strong typing across multiple backend services.
• High-frequency data streaming.

When REST is simpler

• Public APIs consumed by browsers.
• Simple CRUD services.
• CDN caching and easy debugging with curl.

Operational considerations

• gRPC requires HTTP/2 support and compatible tooling.
• Debugging raw gRPC traffic is less human-friendly than JSON.

Checklist

• Need streaming and low latency? Consider gRPC.
• Need public, browser-friendly APIs? REST is usually simpler.
• Do you need strict contracts and code generation? gRPC helps.