aspnetcore/grpc/browser.md
It's not possible to directly call a gRPC service from a browser. gRPC uses HTTP/2 features, and no browser provides the level of control required over web requests to support a gRPC client.
gRPC on ASP.NET Core offers two browser-compatible solutions, gRPC-Web and gRPC JSON transcoding.
gRPC-Web allows browser apps to call gRPC services with the gRPC-Web client and Protobuf.
.proto file..NET has built-in support for gRPC-Web. For more information, see xref:grpc/grpcweb.
gRPC JSON transcoding allows browser apps to call gRPC services as if they were RESTful APIs with JSON.
.proto file with HTTP metadata..NET has built-in support for creating JSON web APIs from gRPC services. For more information, see xref:grpc/json-transcoding.
[!NOTE] gRPC JSON transcoding requires .NET 7 or later.