Skip to main content

REST vs gRPC

Protocol​

  • REST:
    • Built on top of HTTP/1.1 (though it can also use HTTP/2).
    • Uses standard HTTP methods: GET, POST, PUT, DELETE, PATCH.
    • Communication is usually text-based (JSON, XML).
  • gRPC:
    • Built on HTTP/2 by default.
    • Uses remote procedure calls (RPCs) instead of resources + verbs.
    • Communication is binary (Protocol Buffers = compact, fast, strongly typed).

Data Format​

  • REST: JSON (human-readable but larger payload, slower to parse).
  • gRPC: Protobuf (machine-friendly, small size, efficient serialization).

API Style​

  • REST:
    • Resource-oriented (/users/123/orders/456).
    • Loose contracts: schemas are often documented (e.g., OpenAPI/Swagger), but the client can still send unexpected payloads.
  • gRPC:
    • Service-oriented (UserService.GetUser, OrderService.CreateOrder).
    • Strongly typed contracts defined in .proto files. Both server and client code are generated, reducing mismatches.

Streaming​

  • REST:
    • Mostly request-response.
    • Streaming is possible (e.g., Server-Sent Events, WebSockets), but not part of the core REST model.
  • gRPC:
    • Native support for unary RPCs, server streaming, client streaming, and bidirectional streaming.

Performance​

  • REST:
    • JSON + HTTP/1.1 means more overhead.
    • Easier for debugging and testing with curl/browser.
  • gRPC:
    • Binary protocol is much faster, smaller payloads.
    • Designed for low-latency, high-throughput communication.

Compatibility​

  • REST:
    • Universal support (works with browsers, mobile apps, IoT).
    • Great for public APIs.
  • gRPC:
    • Requires client/server code generation.
    • Browser support is limited (though gRPC-Web exists).
    • Great for internal APIs, microservices, and high-performance systems.

When to use which?​

  • Use REST if:
    • You're exposing a public API for third-party developers.
    • You need simple CRUD endpoints.
    • You want wide compatibility (works everywhere with minimal setup).
  • Use gRPC if:
    • You control both client and server.
    • You need fast, strongly typed communication.
    • You want streaming or bi-directional connections.
    • You're building microservices where efficiency matters.