REST vs GraphQL
Compare resource-based API design with query-driven API data selection.
Architecture
REST
REST is an API design style built around resources, endpoints, and standard HTTP methods. It is simple, widely adopted, and fits many traditional web and service APIs well.
Architecture
GraphQL
GraphQL is a query-based API approach where clients specify exactly what data they need. It is useful for flexible frontends and complex data-fetching scenarios.
Key Differences
REST exposes resource endpoints, while GraphQL exposes a query layer where clients ask for exactly the data they need.
REST is usually simpler to reason about operationally, while GraphQL is more flexible for clients with variable data requirements.
GraphQL can reduce over-fetching and under-fetching, while REST often relies on multiple endpoints or fixed response shapes.
REST aligns naturally with HTTP semantics and caching patterns, while GraphQL often requires more deliberate caching strategy.
GraphQL introduces schema and resolver complexity, while REST usually keeps backend behavior easier to trace per endpoint.
The main tradeoff is operational simplicity versus client query flexibility.
When to Use
When to use REST
Use REST when the API surface is straightforward, HTTP semantics matter, caching is important, and the data shape is stable enough to model with clear endpoints.
When to use GraphQL
Use GraphQL when clients need flexible data shapes, multiple related entities in one query, or highly dynamic frontend data requirements.
Tradeoffs
REST is easier to operate and reason about, but may be less flexible for rich frontend data composition.
GraphQL is powerful for clients, but introduces more complexity in schema design, resolver performance, and backend control.
The right choice depends on client needs, operational maturity, and API complexity.
Common Mistakes
Choosing GraphQL just because it sounds more modern.
Using REST when frontend clients constantly struggle with too many calls and rigid payloads.
Ignoring GraphQL performance and resolver complexity in larger systems.
Interview Tip
A strong short answer is: REST is resource-based and simpler operationally, GraphQL is query-based and more flexible for clients.