But what is gRPC, exactly? And why are companies like Google, Netflix, and Dropbox using it to power their services?
In this blog, we’ll break down what gRPC is, how it works, its benefits, and when you might want to use it in your own projects.
What is gRPC?
gRPC (short for gRPC Remote Procedure Call) is a high-performance, open-source framework developed by Google. It allows applications to communicate with each other easily and efficiently, regardless of the programming language they’re written in.
Instead of using HTTP and JSON like REST, gRPC uses HTTP/2 for transport and Protocol Buffers (protobufs) for serialization. This makes it significantly faster and more compact—ideal for real-time, low-latency communication between microservices.
How Does gRPC Work?
gRPC is based on the concept of Remote Procedure Calls (RPCs). This means that instead of sending an HTTP request to an endpoint (like in REST), your code calls a function that lives on another server, as if it were local.
Here’s a simplified breakdown of how it works:
- Define your service in a .proto file using Protocol Buffers.
- Use the gRPC compiler to generate client and server code in your chosen language.
- The client calls a function (e.g., GetUser()), and gRPC handles the networking behind the scenes.
- The server receives the request, processes it, and sends a response—just like a local function call.
This abstraction makes communication more seamless and structured compared to traditional REST APIs.
What Are Protocol Buffers?
Protocol Buffers (protobufs) are a language-neutral, platform-neutral way of serializing structured data. Think of them like a super-efficient alternative to JSON or XML.
Here’s a quick example:
syntax = "proto3";
message User {
string id = 1;
string name = 2;
int32 age = 3;
}
This protobuf schema defines a User object. The gRPC compiler uses this definition to generate code for data serialization and communication.
Benefits of gRPC
Now that you understand what gRPC is, here are some of its key advantages:
???? 1. High Performance
Thanks to HTTP/2 and Protocol Buffers, gRPC is much faster than REST over HTTP/1.1. It supports multiplexing and binary data transfer, which reduces latency and bandwidth.
???? 2. Language Agnostic
gRPC supports multiple programming languages including Go, Java, Python, Node.js, C++, and more. You can build a gRPC service in one language and call it from another with no issues.
???? 3. Built-in Code Generation
The .proto file acts as a single source of truth for API definitions. From it, you can auto-generate consistent server and client code.
???? 4. Streaming Support
gRPC supports bi-directional streaming, making it ideal for real-time communication, such as chat apps, video calls, or live telemetry data.
???? 5. Strong Typing
Since everything is defined in .proto files, gRPC APIs are strongly typed. This leads to fewer bugs and better tooling support.
Bonus Tip: Testing gRPC with Keploy
If you're building gRPC services, testing them can be tricky—especially when it comes to mocking and automation. Tools like Keploy make this easier by recording real gRPC traffic and auto-generating test cases and mocks. It’s a great way to ensure your services behave correctly without writing tons of test logic manually.
When to Use gRPC?
You should consider using gRPC when:
- You need high-performance communication between services
- You’re building a microservices architecture
- You want streaming capabilities
- You’re working in multi-language environments
- You need a more structured and typed API contract
However, for simple public-facing REST APIs, JSON over HTTP might still be more suitable due to its ease of use and widespread adoption.
Conclusion
So, what is gRPC? It's a modern, efficient alternative to REST APIs—built for speed, scalability, and multi-language support. Whether you're building high-performance microservices, internal tools, or real-time data pipelines, gRPC offers a solid foundation for fast and reliable communication.
With tools like Keploy helping you test and maintain your gRPC services, adopting this powerful framework has never been easier.
Read more https://keploy.io/blog/community/what-is-grpc