gRPC vs REST

REST is an architectural style built around resources identified by URLs and manipulated with HTTP verbs like GET, POST, PUT, and DELETE, typically exchanging JSON text that is human-readable but verbose to parse. gRPC instead centers on explicitly defined service methods and messages compiled from a .proto file, exchanged as compact binary Protocol Buffers over HTTP/2. The practical result is that REST favors approachability, browser-friendliness, and loose coupling through hypermedia, while gRPC favors raw performance, strict contracts, and native streaming, which matters most in high-throughput internal service meshes rather than public-facing browser APIs.

Because Protocol Buffers encode data as binary with field numbers instead of repeated string keys, a gRPC payload is typically 3 to 10 times smaller than the equivalent JSON, and parsing it is faster since there is no text tokenization step. HTTP/2's multiplexing also lets gRPC send many concurrent calls over one TCP connection without the connection-per-request overhead that plain HTTP/1.1 REST clients often incur, and combined with built-in code generation, this makes gRPC a strong default for latency-sensitive service-to-service calls inside a data center.

Choose REST when you need broad accessibility from browsers, third-party integrators, or public APIs where human-readable payloads and simple curl debugging matter, and when your consumers value flexibility over strict schemas. Choose gRPC when you control both ends of the connection, such as internal microservices, mobile apps talking to your own backend, or systems needing streaming and low latency, since the strict contract and code generation reduce integration bugs at the cost of needing extra tooling like grpc-web for browser support and less human-readable wire traffic for casual debugging.