In this blog, we’ll explore the key differences between gRPC and REST, when to use each, and how to decide which one best fits your application.
What is REST?
REST (Representational State Transfer) is an architectural style for designing networked applications. It uses HTTP methods like GET, POST, PUT, and DELETE to perform operations on resources identified by URLs. REST APIs typically exchange data in JSON format.
Key Characteristics of REST:
- Human-readable and widely adopted
- Platform-agnostic
- Stateless architecture
- Easy to test with tools like Postman or cURL
- Extensive support across all programming languages
REST is ideal for CRUD-based (Create, Read, Update, Delete) applications and web services where simplicity and interoperability are important.
What is gRPC?
gRPC (gRPC Remote Procedure Call) is a high-performance, open-source RPC framework developed by Google. It leverages HTTP/2 for faster transmission and supports Protocol Buffers (protobufs) as the interface definition language and serialization format.
Key Characteristics of gRPC:
- Uses HTTP/2 for multiplexed streams and better performance
- Strongly typed via Protocol Buffers
- Supports bi-directional streaming
- Offers built-in code generation for client and server stubs
- Ideal for internal microservices and real-time systems
gRPC is especially powerful in microservices architectures, where speed, efficiency, and contract-first development are critical.
REST vs gRPC: Head-to-Head Comparison
| Feature | REST | gRPC |
| Transport Protocol | HTTP/1.1 | HTTP/2 |
| Message Format | JSON | Protocol Buffers (binary format) |
| Performance | Slower due to JSON parsing | Faster due to binary serialization |
| Streaming Support | Limited (HTTP chunking) | Full support (client, server, bidirectional) |
| Browser Support | Excellent | Limited (requires gRPC-Web) |
| Tooling | Simple (Postman, browser, etc.) | Complex (protobufs, generated code) |
| Human Readable | Yes | No |
| Ease of Use | Easier to implement and debug | Requires more setup and tooling |
| Best For | Public APIs, mobile apps, web apps | Microservices, internal APIs, real-time apps |
Use Cases for REST
REST is the go-to solution for many applications, especially when:
- You need a public-facing API (like Twitter or GitHub APIs)
- The clients include web browsers or mobile apps
- The API must be easily consumed and understood by third-party developers
- You want maximum compatibility and ease of debugging
Since REST uses standard HTTP methods and human-readable JSON, it's easy to interact with and quick to get started.
Use Cases for gRPC
gRPC excels in performance-critical and tightly coupled environments. It's ideal when:
- You have many internal microservices communicating frequently
- You need real-time streaming between client and server
- You want strong typing and compile-time validation
- Network performance and serialization efficiency matter
- You need language-agnostic code generation for multiple clients
Because gRPC uses HTTP/2 and binary data, it drastically reduces payload sizes and improves network efficiency.
Which One Should You Choose?
It depends on your project requirements:
Choose REST if:
- You’re building a public API.
- Clients will mostly be browsers or mobile apps.
- Simplicity and readability are top priorities.
- You’re working with teams or developers unfamiliar with protobufs.
Choose gRPC if:
- You’re building a high-performance microservices architecture.
- You need real-time capabilities with bi-directional streaming.
- You want to avoid verbose payloads like JSON.
- Your infrastructure supports modern protocols like HTTP/2.
Real-World Example
Imagine you're building an e-commerce platform:
- Use REST for the frontend web/mobile app, allowing users to browse products or manage accounts.
- Use gRPC for internal services like inventory management, order processing, and analytics where fast and efficient data exchange matters.
This hybrid approach lets you leverage the strengths of both technologies.
Final Thoughts
The choice between gRPC and REST isn’t about one being universally better than the other—it’s about context. REST offers simplicity, readability, and broad compatibility, making it great for many web-based applications. On the other hand, gRPC offers blazing-fast performance, compact messages, and strong typing, making it a smart choice for internal microservices and high-scale environments.
Before making your decision, evaluate the nature of your application, the development ecosystem, and long-term scalability needs.
If you're building for humans, REST might be enough. If you're building for machines, gRPC could be the better fit.
Read more on https://keploy.io/blog/community/grpc-vs-rest-a-comparative-guide