REST vs GraphQL vs gRPC: Differences, Performance, and When to Use
REST vs GraphQL vs gRPC: Differences, Performance, and When to Use
Arslan Ahmad
April 11th, 2026
REST, GraphQL, and gRPC compared: how each one works, the performance trade-offs, and a decision rule for picking one in a system design interview.
Use REST for public APIs and anything a browser calls directly. Use GraphQL when many different clients need different slices of the same data. Use gRPC between internal services where you control both sides and want speed and a strict schema.
That is the short answer. The rest of this guide explains how each one works, what it costs, and how to defend the choice in an interview.
REST vs GraphQL vs gRPC at a glance
| REST | GraphQL | gRPC | |
|---|---|---|---|
| Transport | HTTP/1.1 or HTTP/2 | HTTP, usually one POST endpoint | HTTP/2 |
| Payload format | JSON, text | JSON, text | Protocol Buffers, binary |
| Schema | Optional, via OpenAPI | Required, part of the design | Required, in a .proto file |
| Endpoints | Many, one per resource | One | One method per operation |
| Over fetching | Common | Solved by design | Controlled by the message |
| Browser support | Native | Native | Needs a proxy such as gRPC Web |
| Streaming | Not native | Subscriptions | Built in, both directions |
| Caching | Easy, standard HTTP caching | Hard, most requests are POST | Manual |
| Best fit | Public APIs, wide reach | Many clients, one data graph | Internal service to service |
The decision rule
Three questions settle it almost every time.
Who calls this API? If the answer includes a browser, a third party developer, or a partner you do not control, choose REST. Reach and familiarity beat performance here.
Do different clients need different fields? If one screen needs three fields and another needs thirty, and you are making several round trips to fill a screen, GraphQL earns its complexity.
Do you own both sides? If it is service to service traffic inside your own system, gRPC gives you a strict schema, generated clients, smaller messages, and streaming.
Most real systems end up with two of the three: REST at the public edge, gRPC between internal services.
As a developer, it’s essential to choose the right API development technology for your project. REST, GraphQL, and gRPC are three popular API development technologies that developers use to build scalable, efficient, and reliable APIs.
In this article, I’ll provide a comprehensive comparison of REST, GraphQL, and gRPC. I’ll explore the differences between these technologies in terms of performance, pros and cons, use cases, and how to choose the right technology for your project.
What is REST?
REST stands for Representational State Transfer. It’s a web-based architectural style that developers use to create APIs. REST APIs use HTTP requests to perform operations like GET, POST, PUT, and DELETE. REST APIs are stateless, meaning that each request contains all the necessary information to complete the request. Developers can use REST APIs to communicate between a client and a server.
REST is the most widely used API development technology because it’s easy to learn, scalable, and efficient. REST APIs are easy to cache, making them faster than other API development technologies. REST APIs are also easily accessible from different programming languages.
REST core principles
REST operates on a set of core principles that guide its design and implementation. These principles include:
- Stateless: Each API request is self-contained and carries all the information needed to process it. The server should not store any information about the client’s state between requests.
- Client-Server: The client and server are separate entities that communicate over a network. The client is responsible for the user interface, while the server handles data processing and storage.
- Cacheable: Responses from the server can be cached by the client to improve performance and reduce server load.
- Layered System: RESTful architectures can be composed of multiple layers, each with its own set of responsibilities. This separation of concerns helps improve scalability and maintainability.
- Uniform Interface: RESTful APIs should have a consistent and uniform interface, making them easier to understand and use. Key constraints include using standard HTTP methods (GET, POST, PUT, DELETE) and meaningful URLs.
What is GraphQL?
GraphQL is a query language for APIs that was developed by Facebook. GraphQL allows developers to specify the data requirements of an API request. GraphQL APIs return only the data that the client requested, minimizing the amount of data sent over the network.
GraphQL APIs are more flexible than REST APIs. With GraphQL, developers can get all the data they need in a single request. Developers can also specify the type of data they want to receive from the API. GraphQL APIs are also easier to maintain because they provide a clear understanding of the data requirements.
GraphQL core principles
GraphQL is built on a set of core principles that differentiate it from other API technologies:
- Strongly-typed schema: GraphQL APIs are based on a strongly-typed schema, which defines the types of data, queries, and mutations available. This provides a clear contract between the client and server, making it easier to understand and validate the data being exchanged.
- Hierarchical data structure: GraphQL organizes data in a hierarchical structure, making it simple to represent complex relationships between entities. This mirrors the way data is typically consumed by applications, leading to more intuitive queries and responses.
- Client-driven queries: With GraphQL, clients can request only the data they need, specifying the desired fields and relationships. This eliminates over-fetching and under-fetching, resulting in more efficient data retrieval and reduced network overhead.
- Single endpoint: Unlike REST, GraphQL uses a single endpoint for all data types and operations. This simplifies the API architecture and makes it easier to manage and evolve over time.
What is gRPC?
gRPC is a high-performance API development technology that was developed by Google. gRPC uses Protocol Buffers, a language-neutral, platform-neutral, extensible mechanism for serializing structured data. gRPC allows developers to define services and messages using Protocol Buffers.
gRPC APIs use HTTP/2 for transport, which makes them faster and more efficient than REST APIs. gRPC APIs are also highly scalable because they use HTTP/2 streams to send and receive data. gRPC APIs are also easy to use because they generate client libraries for different programming languages.
gRPC core principles
gRPC is built on several core principles that contribute to its performance and capabilities:
- Protocol Buffers: gRPC uses Protocol Buffers as its serialization format, enabling efficient, binary encoding of data. This reduces the size of messages and minimizes the overhead of parsing and serializing data, leading to faster communication.
- Strongly-typed contracts: gRPC APIs are based on strongly-typed contracts defined using Protocol Buffers, which describe the services, methods, and data types available. This ensures a clear and consistent interface between client and server, reducing the risk of errors and misunderstandings.
- Bi-directional streaming: gRPC supports bi-directional streaming, allowing clients and servers to send and receive messages simultaneously. This enables more efficient communication, especially for large or real-time data transfers.
- Language-agnostic: gRPC is designed to be language-agnostic, with official support for many programming languages, including C++, Java, Python, and Go. This allows developers to choose the most suitable language for their project without worrying about compatibility issues.
Key differences between REST, GraphQL, and gRPC
REST, GraphQL, and gRPC are different API development technologies that have their unique features. Here are some key differences between these technologies:
- Data Transfer: REST APIs transfer data in JSON or XML format. GraphQL APIs transfer data in a GraphQL-specific format. gRPC APIs transfer data in Protocol Buffers format.
- Data Requirements: REST APIs provide all the data available on the server. GraphQL APIs allow the client to specify the data requirements. gRPC APIs use Protocol Buffers to define the messages and services, providing a clear understanding of the data requirements.
- Transport Protocol: REST APIs use HTTP/1.1 for transport. GraphQL APIs use HTTP for transport. gRPC APIs use HTTP/2 for transport.
- Performance: gRPC APIs are faster than REST and GraphQL APIs because they use HTTP/2 for transport and Protocol Buffers for serialization.
- Flexibility: GraphQL APIs are more flexible than REST APIs because they allow the client to specify the data requirements in a single request.
Performance comparison of REST, GraphQL, and gRPC
Performance is a crucial factor when choosing an API development technology. Here’s a performance comparison of REST, GraphQL, and gRPC:
- REST APIs are slower than GraphQL and gRPC APIs because they transfer more data over the network.
- GraphQL APIs are faster than REST APIs because they transfer only the data that the client requested.
- gRPC APIs are the fastest API development technology because they use HTTP/2 for transport and Protocol Buffers for serialization.
Pros and cons of using REST, GraphQL, and gRPC
Here are the pros and cons of using REST, GraphQL, and gRPC:
REST
Pros:
- Easy to learn
- Widely used
- Easy to cache
- Easily accessible from different programming languages
Cons:
- Not flexible
- Slow performance for large data sets
- No clear understanding of data requirements
GraphQL
Pros:
- Flexible
- Faster performance than REST
- Clear understanding of data requirements
- Easy to maintain
Cons:
- More complex than REST
- Requires a learning curve
- Limited community support compared to REST
gRPC
Pros:
- High performance
- Highly scalable
- Easy to use
- Generates client libraries for different programming languages
Cons:
- Limited community support compared to REST and GraphQL
- Requires Protocol Buffers knowledge
- Not widely used compared to REST and GraphQL
Use cases for REST, GraphQL, and gRPC
Each API development technology has its unique use cases. Here are some use cases for REST, GraphQL, and gRPC:
REST
- Simple CRUD operations
- Large data sets with infrequent updates
- Web applications that require caching
Famous uses
- Twitter API: REST API for accessing Twitter data and functionality, including tweeting and user profiles.
- GitHub API: REST API for managing repositories, issues, and pull requests.
- Stripe API: REST-based payment processing API.
GraphQL
- Complex data requirements
- Mobile applications with limited bandwidth
- Data-driven applications that require flexibility
Famous uses
- Facebook API: Developed by Facebook for mobile applications.
- Shopify API: Provides flexible data access for e-commerce.
- GitHub API v4: GraphQL-based version of GitHub API.
gRPC
- High-performance applications
- Microservices architecture
- Applications requiring high scalability
Famous uses
- Google APIs: Built using gRPC for high-performance.
- Netflix APIs: Utilizes gRPC for internal APIs.
- Cisco APIs: Uses gRPC for network management.
Frequently asked questions
What is the main difference between REST, GraphQL, and gRPC? REST exposes many endpoints returning fixed JSON shapes. GraphQL exposes one endpoint, and gRPC exposes typed methods over HTTP/2.
Is gRPC faster than REST? Usually, yes, especially for service-to-service traffic.
Is GraphQL better than REST? Not necessarily better—different, with pros and cons.
Can one system use all three? Yes, and large systems often do. REST for public APIs, GraphQL for client interfaces, and gRPC for internal services.
Conclusion
Choosing the right API development technology is crucial for the success of your project. REST, GraphQL, and gRPC are three popular API development technologies that developers use to build scalable, efficient, and reliable APIs. By considering the factors discussed, you can choose the API development technology that best meets your project requirements.