What Is gRPC?

When you’re building modern software especially systems that need to talk to each other constantly how those systems communicate becomes a big deal. One of the tools we use in our projects is gRPC, and while it’s fast and efficient, it’s definitely not a one-size-fits-all solution. If you’ve been wondering how it stacks up against REST, here’s what we’ve learned from real-world use.

What’s gRPC

gRPC stands for Google Remote Procedure Call, and it’s basically a way for two systems to talk to each other like they’re calling functions locally even though they could be on totally different servers. Google open-sourced it back in 2016, and since then, it’s become a solid option for teams working with microservices, mobile apps, or anything that needs fast and efficient communication.

Instead of using regular old JSON like REST does, gRPC uses Protocol Buffers (Protobuf) a super compact binary format that’s faster and lighter on bandwidth. It also uses HTTP/2 under the hood, which supports cool things like multiplexing and streaming.

gRPC is pretty slick under the surface.

When REST Still Makes Sense

Now, as much as we like gRPC, we’re not here to pretend REST is outdated. REST is simple, familiar, and plays well with just about anything that speaks HTTP. That’s why it’s still the go-to for most public-facing APIs, browser-based apps, and platforms where compatibility matters more than pure speed.

If you’re building something people will access in a web browser, and you want it to just work without extra setup, REST is still your friend.

Where gRPC Shines

Now, if you're dealing with systems behind the scenes like internal microservices, mobile apps, or anything performance-sensitive gRPC can really shine.

Here's why:

• Speed: Protobuf messages are tiny. They travel fast, which helps when you’ve got lots of services passing data all day.

• Streaming: gRPC supports real-time data flow, which is great for things like chat apps, live dashboards, or anything where waiting around for a response just won’t cut it.

• Multilingual Support: You write your API once, and gRPC can generate code for multiple languages Go, Java, Node.js, C#, whatever your stack looks like.

If you’ve got a polyglot team or you’re building stuff in a microservices environment, this can be a huge win.

What About Web Browsers?

here’s the tricky part. Browsers don’t really play nice with gRPC out of the box. That’s where gRPC-Web comes in a kind of workaround that lets web apps talk to gRPC services through a proxy layer. It works, but it’s not perfect.

For example, you won’t get full support for features like bidirectional streaming. If your app really needs to run in the browser without any hiccups, you might want to stick with REST or even consider GraphQL, depending on your use case.

Real Talk: When to Use gRPC (and When Not To)

Here’s the rule of thumb we go by:

Go with gRPC if you:

• Are building internal microservices that need to talk fast

• Are targeting mobile apps where bandwidth and speed matter

• Have a backend-heavy system (especially in Go, Java, etc.)

• Want clean, contract-based APIs with autogenerated client code

Stick with REST if you:

• Need something browser-friendly out of the box

• Are building a public-facing API that’ll be used by lots of third-party developers

• Don’t want to deal with the extra setup of proxies and tools like Envoy

Final Thoughts

We’ve used both gRPC and REST in real-world projects, and the short answer is: it depends.

gRPC is fast, efficient, and built for performance but it comes with some trade-offs. REST is more flexible and universal, but it’s not as speedy. Choosing the right one isn’t just about the tech specs. It’s about what your system needs to do and how your team works.

don’t get too caught up in the hype. Use the tool that fits your situation. And if you’re still not sure? Build a small prototype using both. The answer usually becomes pretty obvious after that.