GraphQL vs JSON-RPC: What are the differences?

Introduction

GraphQL and JSON-RPC are both popular data querying and manipulation protocols used in web development. While both serve a similar purpose, there are several key differences between the two that make them stand out in their own ways.

1. Schema-based vs. Schema-less: One of the fundamental differences between GraphQL and JSON-RPC is their approach to data modeling. GraphQL relies on a strong schema, where the structure and types of the data are defined upfront. This allows clients to request only the specific data they need, reducing unnecessary payload. On the other hand, JSON-RPC is schema-less, meaning there is no predefined structure or type validation for requests or responses.

2. Flexible vs. Fixed Response: GraphQL provides flexibility in terms of response structure. Clients can specify the fields they want to retrieve, and the server returns only those fields. This minimizes the over-fetching of data and reduces network bandwidth. In contrast, JSON-RPC has a fixed response structure defined by the server, where clients receive the entire response object regardless of their specific needs.

3. Single Endpoint vs. Multiple Endpoints: GraphQL uses a single endpoint for all the data fetching and manipulation operations. Clients send a single request to this endpoint, which is then processed by the server to fetch the required data. JSON-RPC, on the other hand, typically involves multiple endpoints, with each endpoint serving a specific operation or method. Clients need to make separate requests to different endpoints for different operations.

4. Strong Typing vs. Dynamic Typing: In GraphQL, strong typing is enforced at the schema level, ensuring that the data passed conforms to the specified types. This provides early validation and reduces the risk of runtime errors. JSON-RPC, being schema-less, allows for dynamic typing, where parameters and return values can have different types in different requests and responses.

5. Bi-directional Communication vs. Request-Response: GraphQL supports bi-directional communication between the client and server. This means that not only can the client request data, but it can also push data to the server using subscriptions and real-time updates. JSON-RPC, on the other hand, operates on a request-response paradigm, where the client sends a request to the server and waits for the response.

6. Cached Responses vs. Fresh Responses: GraphQL enables clients to cache responses efficiently. Since clients specify the exact data they need, they can reuse the cached responses for subsequent requests. This reduces the number of network requests and improves performance. In JSON-RPC, the entire response is sent every time with no built-in caching mechanism, requiring the server to process the request and generate a fresh response for every call.

In summary, GraphQL and JSON-RPC differ in their approach to data modeling, response flexibility, endpoint structure, typing, communication paradigm, and caching. Choosing between them depends on the specific requirements of the application and the desired trade-offs between flexibility and structure.