REST vs GraphQL: When to Use Each (A Developer Who Uses Both Daily)

There's no "best" API protocol, only the best tool for the job. Having built hundreds of endpoints in both REST and GraphQL, here's my practical guide.

[Hero Image: REST vs GraphQL Comparison]

Over-fetching: The REST Problem

In a traditional REST API, calling /api/users/1 might return 40 fields even if you only need the name and email. This is over-fetching.

• REST: 15KB response (3KB needed)
• GraphQL: 3KB response (0 waste)

[Image: Over-fetching Illustration]

The N+1 Problem

When you need a post and its author:

• REST: 1 request for posts + N requests for each author = 11 total requests.
• GraphQL: 1 request with a nested query = 1 total request.

[Image: N+1 Problem diagram]

Decision Framework

| Criteria | Choose REST if... | Choose GraphQL if... | |----------|-------------------|----------------------| | Client Diversity | Single platform | Web, Mobile, IoT (many clients) | | Data Complexity | Simple, flat resources | Highly relational, nested data | | Cacheability | HTTP caching is critical | Data freshness is top priority | | Performance | Low overhead | Precise data selection | | Ultra-low latency | Rust + Actix | Node.js GC pauses matter at <1ms |

[Image: Decision Framework matrix]